Trane ACONT900AC43UA Service Manual
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Trane ACONT900AC43UA Service Manual

Communicating residential comfort systems
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Air Conditioning Procedures
Service Guide
Communicating Residential
Comfort Systems
A Comprehensive Reference for Service of Communicating
Residential Air Conditioning, Heat Pump & Gas Furnace Systems
First Edition
© 2010 Trane Inc.
All rights reserved. No part of this book
may be reproduced, in any form or by
any means, without permission in
writing from the publisher.
Produced and printed in the USA
1.0

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  • Page 1 A Comprehensive Reference for Service of Communicating Residential Air Conditioning, Heat Pump & Gas Furnace Systems First Edition © 2010 Trane Inc. All rights reserved. No part of this book may be reproduced, in any form or by any means, without permission in writing from the publisher.
  • Page 3 We value your opinion. If you feel this service guide can be improved in some way, please give us your thoughts. Simply email your opinion to Loran.dailey@irco.com. You may also write in the space below, tear out this page and mail it to: Trane Company Attn: Loran Dailey 6200 Troup Hwy.
  • Page 5 We value your opinion. If you feel this service guide can be improved in some way, please give us your thoughts. Simply email your opinion to Loran.dailey@irco.com. You may also write in the space below, tear out this page and mail it to: Trane Company Attn: Loran Dailey 6200 Troup Hwy.
  • Page 7 Cautions & Warnings Throughout this manual there are procedures where voltage may be WARNING present and gas or refrigerant system checks may be required. Read all cautions and warnings on this page before proceeding. WARNING WARNING SAFETY HAZARD FIRE OR EXPLOSION HAZARD THIS INFORMATION IS INTENDED FOR USE BY SHOULD OVERHEATING OCCUR, OR THE GAS SUPPLY FAIL INDIVIDUALS POSSESSING ADEQUATE BACKGROUNDS...
  • Page 8 Cautions & Warnings...

  • Page 9: Table Of Contents

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Communicating Controller Section A Introduction ............................3 Product specifications ........................3 Installation ............................3 When installing this product ......................3 Location ............................4 Selecting Comfort Control location ....................4 Sub-base installation ........................
  • Page 10 4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Setpoint deadband ........................21 Backlit display ..........................21 Filter reminders ........................... 21 Fan selections ..........................21 Screen locked ..........................21 Installer system tests ........................21 Default factory settings ........................ 21 Wait indicator ..........................

  • Page 11: Introduction

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup System mode: Heat, Cool, Auto, Emergency Heat, Introduction and Off Fan mode: On, Auto and Circ The (A/T)CONT900AC43UA is a communicating pro- Cooling setpoint temperature range: 60°F to 99°F, grammable Comfort Control (See Table 1) that sup- 1°F resolution ports single-stage or multi-stage heat/cool and heat...

  • Page 12: Location

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Step 2 Selecting Comfort Control location Check the ratings given in the instructions and on the product to make sure the product is suitable for Do not install the Comfort Control where it can be your application.

  • Page 13: Wiring

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Step 5 Figure 3 Use a pencil to mark the mounting holes. Step 6 Remove the sub-base from the wall and drill two 3/ 16” holes in the wall (if drywall) as marked.

  • Page 14: Mounting Comfort Control On Sub-Base

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Step 2 Push the Comfort Control straight onto the wallplate Step 1 (See Figure 4.) Loosen the terminal screws on the sub-base. Insert wires into the terminal block next to the loosened Step 3 screw (See Figure 4.) Perform installation of all other system equipment.

  • Page 15: Communicating Indoor Unit - Communicating Outdoor Unit

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup If no equipment is connected during the Auto-Discov- Adjusting real time clock ery process, the system mode will be stuck at “OFF” and no equipment will run. Setting calendar and time To change the default/discovery settings, enter the in- staller Setup menu (See Table 4, Pages 9-17) and Locate and remove the tab labeled “Remove”...

  • Page 16: Entering Installer Setup

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Figure 7 Figure 6 TCONT900AC43UA Installer’s Guide Step 4 Release the two blank keys when the screen on the Comfort Control matches the screen in Figure 8 (See Figure 8.) Figure 8 Installer setup (ISU)
  • Page 17 4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Step 6 Press the Done key to exit the Installer Setup. Note: Manually changing an ISU setting to an option other than “E” disables Discovery mode for that ISU setting. If power is lost, all custom settings are retained in the memory.
  • Page 18 4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Table 4. Installer Setup Menu Continued. TCONT900AC43UA Installer’s Guide No humidity option available if 3 is selected Note: If single stage is configured, ODU will run Low Stage, but ID airflow ill be 100%.
  • Page 19 4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Table 4. Installer Setup Menu Continued. Note: E1 = Auto discovered w/com ODU E0 = Auto discovered w/o com ODU C - A 11...
  • Page 20 4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Table 4. Installer Setup Menu Continued. TCONT900AC43UA Installer’s Guide Note: Y2 counter only with Phase 2 product (serial date code 0904) if heat demand is satisfied by Y2 - reset timer HP with EH = 0 (no lockout) Dual Fuel = 40 degrees default (Range is 5 - 60)
  • Page 21 4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Table 4. Installer Setup Menu Continued. Not shown if ODU is 2-stage HP and 3 stages of heat are present If “0” is selected, RH% is no longer displayed on the “MORE” screen.
  • Page 22 4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Table 4. Installer Setup Menu Continued. TCONT900AC43UA Installer’s Guide Only shown if ISU0380 is set to 1 or 4 C - A 14...
  • Page 23 4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Table 4. Installer Setup Menu Continued. Phase 2 changes range from 50-90 C - A 15...
  • Page 24 4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Table 4. Installer Setup Menu Continued. Phase 1 = 120 seconds TCONT900AC43UA Installer’s Guide Phase 2 = 0 seconds Phase 1 = 0 seconds Phase 2 = 90 seconds Phase 1 = 0 - disabled Phase 2 = 5 - 1.5 min@100% C - A 16...
  • Page 25 4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Table 4. Installer Setup Menu Continued. C - A 17...

  • Page 26: Operation: Using The Comfort Control

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Operation: Using the Comfort Control • It indicates that the Comfort Control is in Dis- covery mode. System and fan settings Filter indication The system default setting is Heat, unless no Heat stage is discovered/configured.

  • Page 27: Equipment Damage Hazard. Minimum Compressor Off-Time Is Bypassed During Installer System Test

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup toggle between the main screen and a screen show- The Installer Test is part of the Installer Setup op- ing the Alert code number. When multiple Alert codes tions.

  • Page 28: Control Response Rate

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Table 6. Installer System Tests Continued. TCONT900AC43UA Installer’s Guide recommended that the fan only be used in the each ON/OFF cycle would be 20 minutes long when AUTO mode. operating at 50% load.

  • Page 29: Backlit Display

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Setpoint deadband Fan selections The number of degrees separating Heating and Cool- Pressing the Fan key selects whether the indoor fan ing setpoints is user adjustable from two to nine de- motor runs in the On, Automatic, or Circulation mode.

  • Page 30: Wait Indicator

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup to factory defaults in Auto-Discovery mode. sor becomes unavailable, no outdoor value will be displayed. The Comfort Control will not send an Alert. Wait indicator Humidification “Wait” will be displayed when the setpoint is changed Indoor humification control in the direction of calling for additional system ca- pacity or the outdoor unit is in Charge Assist™...

  • Page 31: Droop

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup dehumidification setpoint is 50%. In extremely high the indoor humidity is above the dehumidification humidity conditions, the Comfort Control keeps the setpoint. This will help reduce coil condensation from compressor running for up to 3°F (-1.7°C) below the being evaporated back into the air stream.

  • Page 32: Operation In Heat Mode

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup auxiliary heat operation and will turn off the heat pump. If the outdoor temperature sensor has not been dis- During defrost, this outdoor temperature setting is ig- covered/enabled, the stage or combination of stages nored and the defrost heater balance point outdoor to be used during defrost can be set in Installer Setup temperature thresholds are used.

  • Page 33: Troubleshooting Guide

    4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Step 2 If heat pump auxiliary lockout was selected, in Installer Setup number 0345, choose appropriate Heat Pump Auxiliary Lockout Temperature in Installer Setup number 0360. Step 3 Choose appropriate Defrost Balance Point Tempera- tures in Installer Setup numbers 0361-0363.
  • Page 34 4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Table 7. Troubleshooting Information. TCONT900AC43UA Installer’s Guide Table 7. Troubleshooting Information Continued. C - A 26...
  • Page 35 4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup Table 7. Troubleshooting Information Continued. C - A 27...
  • Page 36 4 Heat/3 Cool/ Heat Pump (A/T)CONT900AC43UA Installer Guide Communicating Programmable 3-Wire Hookup TCONT900AC43UA Installer’s Guide C - A 28...
  • Page 37 Air Conditioning and Heat Pump Procedures Communicating Air Conditioning and Heat Pump Systems Sequences of Operation ..................A Control Boards ......................B EEV Tests ........................ C Sensor Tests ......................D Sump Heater ......................E Outdoor Fan Motor ....................F Refrigeration Cycle Problems ................G...
  • Page 39 Sequences Of Operation Communicating Air Conditioning and Heat Pump Systems Section A 16 SEER .............................. 2 Air Conditioner and Heat Pump models ..................2 Charge Assist™ ..........................4 Power Interrupt Delay ........................4 Heat Pump Cooling Mode of Operation ..................4 Defrost Mode ..........................

  • Page 40: 16 Seer

    Sequence Of Operation 16 SEER Sequence of Operation 3) Y2 LED: When a request for second stage capacity is sent 16 SEER from the communicating comfort control, the outdoor control will respond by sending a 20 volt DC signal from the J5 plug Operation of the communicating outdoor unit is managed and on the control board to the compressor solenoid.
  • Page 41 Sequences Of Operation 16 SEER Sequence of Operation HP - A 3...

  • Page 42: Charge Assist

    Sequence Of Operation 16 SEER Sequence of Operation Refer to the schematic diagram on page 3 11) ODT Out Of Range LED: Outside temperature must be at least 55 degrees F to enter Charge Assist™. If the outside Charge Assist™ temperature is sensed to be low, based on input from the Ambient Temperature Sensor, this LED will flash for 30 seconds followed See the Service Facts in the outdoor unit for detailed information...

  • Page 43: Defrost Mode

    Sequences Of Operation 16 SEER Sequence of Operation 1. Comfort control demand could be satisfied and turn off the Defrost Mode equipment. 2. Comfort control demand could request the system to run 1 During the heating cycle, the outdoor coil may become frosted stage heating mode.

  • Page 44: 20 Seer

    Sequence Of Operation 20 SEER Sequence of Operation 3) Y2 LED: When a request for second stage capacity is sent 20 SEER from the communicating comfort control, the outdoor control will respond by turning OFF the first stage compressor. 24 Operation of the communicating outdoor unit is managed and volts AC output will be removed from the J3/1 (Y1) plug de-...
  • Page 45 Sequences Of Operation 20 SEER Sequence of Operation HP - A 7...

  • Page 46: Charge Assist

    Sequence Of Operation 20 SEER Sequence of Operation Refer to the schematic diagram on page 7 11) ODT Out Of Range LED: Outside temperature must be at least 55 degrees F to enter Charge Assist™. If the outside temperature is sensed to be low, based on input from the Ambient Charge Assist™...

  • Page 47: Heat Pump Heating Mode Of Operation

    Sequences Of Operation 20 SEER Sequence of Operation Heat Pump Heating Mode of Operation Defrost Mode Electronic Expansion Valve (EEV) During the heating cycle, the outdoor coil may become frosted The EEV control board receives up to 5 analog signals from or iced-up which reduces system capacity.

  • Page 48: Defrost Termination To Second Stage Heating Cycle

    Sequence Of Operation 20 SEER Sequence of Operation 5. Comfort control demand could request the system to run 4 Refer to the schematic diagram on page 7 stage heating mode. a. For heat pump systems with electric auxiliary heat, Defrost initiation from second stage heating cycle this is 2 stage compressor with 2 stage auxiliary...
  • Page 49 Control Boards Communicating Air Conditioning and Heat Pump Systems Section B 20 SEER Heat Pump Model Control Boards ..................2 Overview ............................2 Sump Heater Control ........................2 Sump heater operation at power up ..................2 High Pressure Monitor Logic ......................3 Low Pressure Monitor Logic ......................

  • Page 50: 20 Seer Heat Pump Model Control Boards

    Control Boards Sump Heater Control 20 SEER Heat Pump Model Control Boards Sump heat protects the compressor from liquid Overview migration. Liquid migration occurs when refrigerant migrates during off cycle periods into the compressor Communicating product air conditioners and heat shell.
  • Page 51 Control Boards The integrated control board will monitor system pres- Figure 2 sure via the Liquid Pressure Transducer and will monitor the HPCO. If it senses an open HPCO event, will start a 5 minute wait period where the compressor is shut off.

  • Page 52: Cool Mode Lpco Logic

    Control Boards The switch is wired directly to plug J4 (LPCO) (Figure Low Temp Lockout in Cool Mode 7&8) on the Integrated Control Board. If the LPCO opens and the Outdoor air temperature is Typical causes of low system pressure include under below 50F, the unit will remain locked out of cooling charging, refrigerant leaks, lack of air volume, and operation until the outdoor air temperature reaches 60F.

  • Page 53: Sensor And Control Voltage Fault Detection

    Control Boards Graph 6 Low temp cooling A/C trip points Graph 3 Sensor and Control Voltage Fault Detection The Integrated Control Board has the capability to de- Graph 4 tect and report a Liquid Pressure Sensor (see Figure 9) fault and a loss of control voltage at the Y1 connec- tion on plug J1 (see figure 10).

  • Page 54: Power Interruption Protection

    Control Boards Figure 10 The Oil Return Mode may also be initiated below 45' F after 8 hours of cumulative low stage compressor op- eration. Any Defrost cycle will reset the Oil Return Mode timer. Any high stage compressor operation (for at least 5 uninterrupted minutes) will reset the low stage run timer at any outdoor air temperature.

  • Page 55: Charge Assist Feature All Models

    Control Boards • Ambient Sensor fault (open) = Oil Return Mode Defrost Component Electrical Wiring exits allowing Defrost Control to assume low tem- perature below 6' F (Defrost every 3 hours) The Coil Sensor (see Figure 13) is a negative coeffi- •...

  • Page 56: First Defrost Event

    Control Boards The outdoor fan motor connects to the control board Terminate Temps on Plug J3. During defrost, the motor is off. Service Facts shipped with the outdoor unit contains a table of If the outdoor air temperature is above 6F, the maxi- PWM voltage requirements that can be checked to mum time in defrost is 15 minutes.

  • Page 57: Demand Defrost Control Checkout

    Control Boards FIGURE 6. OUTDOOR CONTROL 16 SEER Control Board BOARD - PIN IDENTIFICATION PIN IDENTIFICATION (SEE FIGURE 6.) 1. TEST_COMMON (Shorting any of the other pins to this pin causes the function of the other pin to be executed. Leaving this pin open results in the normal mode of operation.) 2.
  • Page 58 Control Boards HP - B 10...
  • Page 59 Electronic Expansion Valve (EEV) Test Communicating Air Conditioning and Heat Pump Systems Section C Overview ............................. 2 Problems ............................3 Troubleshooting the EEV ........................3 Electronic Expansion Valve (EEV) control board ................3 How to test ............................4 Close valve test ..........................4 Open valve test ..........................

  • Page 60: Overview

    Electronic Expansion Valve (EEV) Test Overview The EEV adjusts its internal orifice size in small incre- ments via commands from the EEV board. The EEV Some communicating system heat pumps use a spe- stepper motor coil connects to the circuit board at cial expansion valve called an EEV (Figure 1) in the connector J1.

  • Page 61: Troubleshooting The Eev

    Electronic Expansion Valve (EEV) Test Troubleshooting the EEV Fault LED (Red) (Figure 2) Flashing pattern: See Table 2. The Electronic Expansion Valve (EEV) installed in this Table 2 heat pump is designed to control superheat entering the compressor when the system is running in me- chanical heating mode.

  • Page 62: How To Test

    Electronic Expansion Valve (EEV) Test How to test Open valve test Close valve and open valve tests are active in any mode 1. Touch OPEN pin to TEST pin (Figure 5). of operation Figure 5 Test Pins: Open, close, test (Figure 2) Close valve test 1.

  • Page 63: Troubleshooting Flow Chart

    Electronic Expansion Valve (EEV) Test Troubleshooting Flow Chart EEV is not sensing that the compressor is ON and in the Heat Mode. 1.) Check plug & harness at J6. System is pumping down 2.) Verify 24VAC at Y1 and/or Y2 inputs to EEV control J6 are in heat mode present (not “O”) See Table 1.
  • Page 64 Electronic Expansion Valve (EEV) Test HP - C 6...
  • Page 65 Sensor Tests Communicating Air Conditioning and Heat Pump Systems Section D Testing the suction line temperature sensor .................. 2 Introduction ............................ 2 Testing voltage across temperature sensor ..................2 Ohm meter ............................. 2 Testing the suction line pressure transducer ................. 3 Introduction ............................
  • Page 66 Sensor Tests Testing the suction line temperature sensor Figure 3 Figure 2 Introduction The suction line temperature sensor (Figure 1) is a negative coefficient type thermister that changes electrical re- sistance with changes in temperature. Performed at the When the temperature it senses drops, the resistance of the sensor will in- EEV board crease.
  • Page 67 Sensor Tests Figure 7 Step 3 Use an ohmmeter to measure the resistance of the suction line sensor (Figure 5). Compare to Table 1 values. If the sensor resistance is not equal to or close to the table values, replace the sensor. Figure 5 Step 2 Measure the DC voltage between the VP point and...
  • Page 68 Sensor Tests Testing the liquid line temperature sensor Figure 11 Introduction The liquid line temperature sensor (Fig- ure 9) is a negative coefficient type thermister that changes electrical re- sistance with changes in temperature. When the temperature it senses drops, the resistance of the sensor will in- crease.
  • Page 69 Sensor Tests Step 3 Figure 15 Use an ohmmeter to measure the resistance of the liquid line sensor (Figure 13). Compare to Table 3 values. If the sensor resistance is not equal to or close to the table values, replace the sensor. Figure 13 Step 2 Measure the DC voltage between the +VP point and...
  • Page 70 Sensor Tests HP - D 6...
  • Page 71 Sump Heater Communicating Air Conditioning and Heat Pump Systems Section E Overview ............................. 2 Troubleshooting ..........................2 Sump heater fails to energize ......................2 Sump heater fails to turn OFF during compressor operation ............3 HP - E 1...
  • Page 72 Sump Heater Overview Figure 1 Sump heat protects the compressor from liquid migration. Liquid migration occurs when refrigerant migrates during off cycle periods into the compressor shell. Keeping the compressor shell warm during off cycle periods can prevent liquid migration. Troubleshooting If the sump heaters fail to energize, the compressor If voltage is not present, check for 24 volts at the...
  • Page 73 Sump Heater If the relay is closed, 0 volts should be present. If line Step 3 voltage is measured, the relay contacts are open and If 0 volts is measured between the Sump Heater Relay the Sump Heater Relay is defective. Replace the Sump terminals 1 and 3, measure the voltage potential Heater Relay.
  • Page 74 Sump Heater HP - E 4...
  • Page 75 Outdoor Fan Motor Communicating Air Conditioning and Heat Pump Systems Section F Introduction ............................2 Troubleshooting ..........................2 HP - F 1...
  • Page 76 Outdoor Fan Motor Introduction Step 3 With line voltage verified, check for the motor speed Communicating outdoor unit models feature ECM type command from the control board. Set digital outdoor fan motors. The motors are powered by 240 multimeter to read DC voltage. Check for DC voltage volt line voltage and are speed controlled via a PWM between TEST COMMON and the PWM pin on plug J3 of the outdoor unit control board (Figure 3).
  • Page 77 Refrigeration Cycle Problems Communicating Air Conditioning and Heat Pump Systems Section G Check Procedures Filter drier check ..........................2 Reversing valve check ........................2 Cooling Mode ........................... 2 Heating Mode .......................... 3 HP - G 1...
  • Page 78 Refrigeration Cycle Problems Note: Troubleshooting liquid line filter driers and check Check Procedures valves (when not in the checked position) is similar. Both components should allow a free flow of refrigerant Filter Drier Check without restriction. A 3degree F temperature drop across a check valve indicates a restricted screen The filter drier functions to remove debris and internal in the check valve.
  • Page 79 Refrigeration Cycle Problems Step 2 Step 4 If voltage is present, shut the system down, discon- If no voltage is present at the coil during a call for nect power to the unit, remove one wire from the coil, cooling, check for 24 volts at the defrost control board and perform an Ohms check on the coil (Figure 3).
  • Page 80 Refrigeration Cycle Problems Step 2 Step 4 The reversing valve 24 volt coil will become energized Let the unit run for several minutes, then force a de- and the valve will shift. If not, check for the presence of frost cycle again. Place the metal end of a screw- 24 volts at the coil (Figure 7).
  • Page 81 Charge Assist™ Communicating Systems Charge Assist Section A Sequence of Operation ..........................2 Control LED Indications ..........................2 Installer’s guide for BAYCAKT001AA Charge Assist™ Tool ..............3 Connecting The Charge Assist™ Tool .................... 3 Charge Assist™ Procedure with a Communicating Comfort Control ............ 4 Parameters for using Charge Assist ....................

  • Page 82: Sequence Of Operation

    Charge Assist™ Note: Control LED Indications The Charge Assist™ Procedure Details are for educational purposes only. Please refer to the most recent documents Figure 1 for updated material before engaging in any of these tests and procedures Sequence of Operation The OUTDOOR UNIT’S Charge Assist ™(CA) Control Board, is a microprocessor based control which can communicate digitally with a communicating system’s...

  • Page 83: Installer's Guide For Baycakt001Aa Charge Assist™ Tool

    Charge Assist™ • Com LED Flashing = The number of Flashes equals Figure 2 the number of communicating controls talking on the Data Line. Example: A communicating system thermostat + a communicating indoor unit + a communicating outdoor unit = Three Flashes. •...

  • Page 84: Charge Assist™ Procedure With A Communicating Comfort Control

    Charge Assist™ Step 1-D Step 5 Re-tighten and turn knob back to off. Follow instructions for Charge Assist Procedures Step 1-E Step 6 Connect the interface cable from the tool to the cir- The Green LED on the Charge Assist Tool will turn cuit board at the “charge solenoid”...

  • Page 85: Parameters For Using Charge Assist

    Charge Assist™ Using Charge Assist Parameters for using Charge Assist Outdoor Temperature (ODT): Step 1 Must be between 55°F and 120°F for R-410A systems Press MODE button (See Figure 8) for 2 seconds to (between 65°F and 100°F for R-22 systems) . If ODT enter the CA mode.

  • Page 86: Charged Routine

    Charge Assist™ Step 2 CHARGED Routine Enter Stabilization Routine - The CHARGING (STABILIZING) Amber LED (Figure 10) will begin to If the CA control determines the system is correctly charged, the CHARGING (STABILIZING) Amber LED flash. will be turned OFF and the CHARGED Green LED Figure 10 will be turned ON (Figure 12).

  • Page 87: Add Routine

    Charge Assist™ ADD Routine Note: For Manual Charging Once sufficient charge has been added, the Amber ADD LED will turn OFF and the Green CHARGED LED will be If the CA control determines refrigerant is required, turned ON. When the Amber ADD LED turns OFF; stop the ADD Amber LED will turn ON and the Green adding refrigerant.

  • Page 88: Charge Assist™ Procedure For A Non-Communicating 24Vac Control System

    Charge Assist™ STEP 4 NOTE: Charge Assist™ IS NOT allowed when a heat After the CA control exits the CA mode CYCLE, the pump is operating in the heating cycle. If the mode button is pressed during an active compressor heat call, the technician must then...
  • Page 89 Charge Assist™ Step 3 Set the indoor system control to call for second stage cooling throughout the charging process (Figure 18). Note: If using a communicating comfort control, this step is not required as the system will perform this task once Charge Assist mode is started.
  • Page 90 Charge Assist™ Figure 20 CA - A 10...

  • Page 91: Adjusting System Charge Without Charge Assist

    Charge Assist™ Step 3 Adjusting System Charge WITHOUT Charge The system may need to run up to 20 minutes to sta- Assist Tool BAYCAKT001AA (Solenoid Kit) bilize. Step 1 Note: During system stabilization, the STABILIZING LED will flash. Hook-up gauges to the refrigerant bottle and the Charge Assist port (Figure 21).

  • Page 92: Adjusting System Charge With Charge Assist

    Charge Assist™ Step 3 Adjusting System Charge WITH Charge Start Charge Assist by pressing the MODE button Assist Tool BAYCAKT001AA (Solenoid Kit) for a minimum of 2 seconds (Figure 27). Step 1 Figure 27 Hook-up the solenoid to the refrigerant bottle and the Charge Assist port (Figure 24).
  • Page 93 Charge Assist™ Yes: The Charge Assist™ control is communicat- Charge Assist Troubleshooting ing with the control system. Go to Step 3. Troubleshooting the Charge Assist Control The COM LED is flashing fast, go to the trouble shooting ERR code 89 or 91 section. Step 1 Is there 24 volts AC at the Charge Assist™...
  • Page 94 Charge Assist™ Yes: Go to Step 6. Step 6 Is there 24 volts AC at plug J3 between its pins Y1 and On an AC unit, replace the Charge Assist™ B (Figure 34) or Y2 and B (Figure 35)? Control. Heat pump units only check for 24 volts Note: There should be 24 volts present only between AC across Charge Assist™...

  • Page 95: Troubleshooting Charge Assist

    Charge Assist™ Troubleshooting Charge Assist Control Fault LED flash codes of 2, 3 or 4 flashes LED Flash Codes Go to defrost control troubleshooting procedures. If the comfort control is displaying Err code 89 or 91 or These faults are not reported to the Comfort Control as Err codes.
  • Page 96 Charge Assist™ Does the ambient temperature and the DC voltage or the sensor plugged in or unplug the sensor and read its resistance in ohms read at the Ambient Tempera- the resistance of the sensor (Figure 39). ture Sensor plug J7 agree with the temperature, resis- Figure 39 tance and voltage chart? (See Reference Materials) Yes:...

  • Page 97: Fault Led Flash Code Of 7, Err Code #79

    Charge Assist™ Figure 41A Figure 41B Figure 40 Fault LED flash code of 7, Err code #79 Fault LED flash code of #10 This fault code only applies to the Heat Pump models This fault will only appear when the Charge Assist™ in the heating or cooling cycle.
  • Page 98 Charge Assist™ Does the liquid line temperature and the DC voltage or Figure 44 resistance read at the Liquid Temperature Sensor plug J8 agree with the temperature, resistance and voltage chart? (See Reference Materials) Yes: Unplug and re-plug the Liquid Line Tempera- ture Sensor (Figure 43) several times to insure it is making good contact with the control pins.
  • Page 99 Charge Assist™ Yes: Turn off the 24 volts A/C to the Charge As- Figure 45A Figure 45B sist™ Control and then re-power the control. If the 13 flash codes continue to be displayed, replace the Charge Assist™ Control. Note: Disconnect the External Ambient Temperature Sensor and re-power the control system.
  • Page 100 Charge Assist™ Fault LED flash code of 15 This indicates that there are multiple External Ambi- ent Temperature sensors installed. Only one or four sensors can be connected to the EXT. terminal board on the Charge Assist™ Control. CA - A 20...
  • Page 101 Charge Assist™ CA - A 21...
  • Page 102 Charge Assist™ CA - A 22...
  • Page 103 Air Handler Communicating Air Handler Section A Introduction ............................... 2 Air Handler Interface Display Assembly ....................2 24VAC Fuse ............................2 Control Board ............................3 Serial Port Variable Speed Motor ......................3 Electric Heater Terminals ........................3 Humidifier Terminals - (HUM)......................... 3 Electronic Air Cleaner Terminals (EAC) ....................

  • Page 104: Introduction

    Air Handler An air handler’s auxiliary heat will turn off at once. Introduction There will be a several second delay before the indoor blower is shut down. The User Interface Assembly will Air Handler Interface Display Assembly display CHECK FUSE under indoor alerts. The air handler can operate using the Communicating System or with 24VAC thermostat inputs.

  • Page 105: Control Board

    Air Handler Humidifier Terminals - (HUM) Control Board (Figure 1 ) A set of N.O. contacts (¼” QC male Serial Port Variable Speed Motor terminals) will close for operation of a humidifier when the control is in heating mode and the blower is A 4-wire harness (Figure 1 ) enables operating.

  • Page 106: Bit Master (Bm) Led

    Air Handler Bit Master (BM) LED Fault LED BM / Clock Signal LED Green (Figure 1 The Fault LED will be turned on at power-up and will - LED on when AHC Clock is working. remain on for a short time period and then turned off. When no faults are present, the Fault LED will blink COM LED once every 20 seconds.

  • Page 107: Sequence Of Operation

    Air Handler cooling is received, the blower will be de-energized Sequence of Operation once any user selected fan-off delays have expired. The Charge Assist™ Control in the outdoor unit will Communicating Mode control the sequence of the compressor(s) and the outdoor fan speed.

  • Page 108: Heat Pump & Electric Heat Applications

    Air Handler • When only one stage of Cooling is selected, the indoor blower speed will default to Cooling HI fan speed. Heat Pump & Electric Heat Applications • When two stages of Cooling are selected, the 1st stage CFM can be selected via the User Interface (Communicating Heat Pump) Assembly.

  • Page 109: Electric Heat Only Sequence - 24Vac Input

    Air Handler Electric Heat Only Sequence – 24VAC Input Heat output will be de-energized. • When Y1 and Y2 inputs are removed, the 2nd stage • When the W1 and G are present, the control will compressor will turn off. When G is removed, the energize the 1st heater contactor and blower at the corresponding compressor stage will cycle off after heating speed selected via the User Interface.

  • Page 110: Communicating Systems Troubleshooting Checklist

    Air Handler • After 1 second energize stage 2 heat relay • After 1 more second energize stage 3 heat relay • After 5 seconds de-energize blower interlock, stage 1, 2 & 3 heat relays (User Interface displays UNIT TEST – EXIT) •...

  • Page 111: Service Bulletins

    Air Handler Service Bulletins Page 1 of 2 AH - A 9...
  • Page 112 Air Handler Page 2 of 2 AH - A 10...
  • Page 113 Air Handler Page 1 of 3 AH - A 11...
  • Page 114 Air Handler Page 2 of 3 AH - A 12...
  • Page 115 Air Handler Page 3 of 3 AH - A 13...
  • Page 116 Air Handler AH - A 14...
  • Page 117 Furnace Procedures Communicating Gas Furnace Furnace Sequences of Operation ................A Inducer Motors ......................B Pressure Switches ....................C Gas Valves ....................... D Silicon Nitride Ignitor ....................E Measuring Flame Current ..................F Flame Rollout Switches ..................G Indoor Blower Motor ....................H Main Air Limit Switch ....................
  • Page 119 Furnace Sequences Of Operation Communicating Gas Furnaces Section A Communication Mode ........................2 Indoor Blower motor operation thermostat fan switch “ON” ............3 24VAC Mode ............................4 Thermostat call for W2 after W1 ....................4 W2 satisfied, W1 still called for ..................... 4 W1 satisfied ..........................

  • Page 120: Communication Mode

    Furnace Sequences Of Operation Communication Mode 9. The IFC verifies ignition by the flame current Communication Mode sensing method. If a flame is not detected, the IFC will cycle the furnace three times to try and verify 1. This furnace is fully modulating between 40% and a flame.
  • Page 121 Furnace Sequences Of Operation Communication Mode 18. The IFC then signals the variable speed inducer drive to ramp up the vent motor steps. As the vent motor speed increases the amount of gas coming through the gas valve will increase. The IFC will also increase the indoor blower motor speed.

  • Page 122: 24Vac Mode

    Furnace Sequences Of Operation 24VAC Mode 10. After 45 seconds, the IFC signals the indoor blower motor 24 VAC Mode to run at the programmed ignition sequence speed. 1. This furnace modulates between 40% and 100% of capacity, 11. The IFC then signals the variable speed inducer motor in 3% increments, every 1 minute.

  • Page 123: Indoor Blower Motor Operation Thermostat Fan Switch "Continuous

    Furnace Sequences Of Operation 24VAC Mode Note: The furnace lights at approximately 65% of capacity. 18. The IFC receives a 24 VAC signal from PS1 and PS2 when they close. This verifies the vent motor is moving the correct amount of combustion air through the furnace and the vent system.

  • Page 124: Ifc Inducer Learning Routine Sequence

    Furnace Sequences Of Operation IFC Inducer Learning Routine Sequence · If PS-1 and PS-2 do not close at the preset IFC Inducer Learning Routine Sequence factory 65% (medium) heat RPM, the furnace IFC will continue to signal the variable speed inducer drive Note: to increase the inducer speed in steps until PS- Stage 1 = 40% (low) heat, Stage 2 = 100% (high) heat...
  • Page 125 Furnace Sequences Of Operation IFC Inducer Learning Routine Sequence · The furnace IFC now stores this learned operating inducer RPM for 65% (medium) heat in its memory. · The furnace IFC will use this stored learned operating inducer RPM for 65% (medium) heat calls it receives in the future.
  • Page 126 Furnace Sequences Of Operation High Heat Inducer Learning Routine · The furnace IFC then adds an additional number High Heat Inducer Learning Routine of RPM to the 100% (high) heat inducer motor NOTED RPM until PS-3 closes. Note: Stage 1 = 40% (low) heat, Stage 2 = 100% (high) heat ·...
  • Page 127 Furnace Sequences Of Operation High Heat Inducer Learning Routine GF - A 9...

  • Page 128: Alert Code Recovery

    Furnace Sequences Of Operation Alert Code Recovery Alert Code Recovery On power up, last 4 Alerts, if any, will be flashed on the Red Alert LED. The newest Alert detected will flash first and the oldest last. There will be a 2 second delay between Alert Code flashes.
  • Page 129 Furnace Sequences Of Operation Alert Code Recovery GF - A 11...
  • Page 130 Furnace Sequences Of Operation Three-Stage Gas Furnace The comfort control thermostat (17) will continue to call for Three-Stage Gas Furnace first stage heat operation until the indoor temperature is back at The comfort control thermostat signals (17) the Furnace IFC the comfort control thermostat set point or, if the comfort control for First Stage Heat.
  • Page 131 Furnace Sequences Of Operation Three-Stage Gas Furnace The comfort control thermostat will continue to monitor the indoor temperature and send signals to the IFC to operate at different stages or go to off so it can maintain the indoor temperature at the homeowner’s set point. GF - A 13...

  • Page 132: Comfort Control Call For 1St Stage Heat ((A/T)Cont900)

    Furnace Sequences Of Operation UD2 Communicating Mode UD2 Communicating Mode 1st stage satisfied The comfort control signals that the 1st stage heating Comfort control call for 1st stage heat ((A/T)CONT900) requirements have been satisfied. The 1st stage gas valve will be de-energized and gas flow will cease. The draft The comfort control signals the control board (IFC) to run its...
  • Page 133 Furnace Sequences Of Operation UD2 Communicating Mode GF - A 15...

  • Page 134: Ud2 24V Mode

    Furnace Sequences Of Operation UD2 24v Mode UD2 24v Mode 1st stage satisfied Thermostat call for 1st stage heat (2 stage heating and W1 thermostat contacts open signaling that the 1st thermostat) stage heating requirements have been satisfied. The 1st stage gas valve will be de-energized and gas flow will cease.

  • Page 135: Indoor Blower Motor Operation Thermostat Fan Switch "On

    Furnace Sequences Of Operation UD2 24v Mode If the furnace was operating on 1st stage heat, the indoor motor will operate at 1st stage heating airflow for the duration of the 1st stage heating fan off delay. Indoor Blower motor operation thermostat fan switch “ON”...

  • Page 136: Alert Code Recovery

    Furnace Sequences Of Operation Alert Code Recovery Alert Code Recovery On power up, last 4 Alerts, if any, will be flashed on the Red Alert LED. The newest Alert detected will flash first and the oldest last. There will be a 2 second delay between Alert Code flashes.
  • Page 137 Furnace Sequences Of Operation Alert Code Recovery IFC Board GF - A 19...
  • Page 138 Furnace Sequences Of Operation *UH3 Sequence of Operation · The IFC then signals the variable speed inducer motor drive UH3 Sequence of Operation board (8) to ramp down the vent motor in steps to the first stage vent motor speed. The reduction of the vent motor speed in steps allows the gas flow through the gas valve to also be reduced in steps.
  • Page 139 Furnace Sequences Of Operation *UH3 Sequence of Operation · The communicating comfort control will continue to monitor the indoor temperature and send signals to the IFC to operate at different stages or turn off so that it can maintain the indoor temperature at the homeowner’s set point.

  • Page 140: Uh3 Inducer Learning Routine Sequence

    Furnace Sequences Of Operation *UH3 Inducer Learning Routine Sequence UH3 Inducer Learning Routine Sequence The furnace IFC now signals the variable speed indoor blower to run at the programmed second stage heating The furnace IFC will go through an inducer learning routine airflow.
  • Page 141 Furnace Sequences Of Operation *UH3 Inducer Learning Routine Sequence The furnace will start the heating cycle in second stage, if not already on, and then begins the third stage learning routine. The furnace checks pressure switch three, PS-3, it must be open. When the furnace IFC detects that PS-3 is open, it will...
  • Page 142 Furnace Sequences Of Operation GF - A 24...
  • Page 143 Induced Draft Motors Communicating Gas Furnaces Section B Variable Speed Three Phase Induced Draft Motors ....................Introduction ............................2 Electrical circuit ............................ 2 Sequence of operations ........................2 First stage learning routine ........................2 Vent pressure switch must be open prior to motor starting ..............3 Learning routine ............................
  • Page 144 Induced Draft Motors Variable Speed Three Phase Induced Draft Motors connector connects the three phase motor to the elec- trical harness (Figure 2.) Introduction Figure 2 Late model *UY/DY and all *UH/DH, except UH1/DH1, furnace models feature variable speed three phase in- duced draft blowers.
  • Page 145 Induced Draft Motors a learning routine to learn the optimum operating nsitions open. The IFC then increases the vent mo- speed. The adaptive learning routine begins on the tor RPM by three hundred RPM and stores this learned first call for heat anytime that the POWER has been RPM in its memory and uses it for the next one hun- CYCLED or the integrated furnace control has done dred and fifty times when the first stage is called for.
  • Page 146 Induced Draft Motors stage heat. If PS-2 does not transition open during Troubleshooting this learning routine, the IFC will shut the furnace heating cycle down, send a three flash code, wait Step 1 thirty seconds and will restart the first stage heating If the induced draft blower motor does not run during a cycle again if there is still a call for heat.
  • Page 147 Induced Draft Motors Measure the resistance of the three phase motor Step 3 windings L1 to L2 (See Figure 5), L2 to L3 (Figure 6), Check the resistance of L1, L2, and L3 to the green L1 to L3 (Figure 7.) Equal resistance should be ground wire on the plug of the induced draft blower measured through all combinations of motor windings.
  • Page 148 Induced Draft Motors Step 4 Make sure the motor wheel spins freely and debris is not preventing it from operating. If the motor wheel spins freely, all motor winding combinations have equal resistance and are not shorted to ground, the motor is not at fault.
  • Page 149 Pressure Switches Communicating Gas Furnaces Section C Pressure switch testing ........................2 GF - C 1...
  • Page 150 Pressure Switches Pressure switch testing Step 3 Check for 24 Volts AC coming to the pressure switch, Step 1 see drawing # 3. Connect one lead of the AC Volt Connect a slope gauge or magnehelic gauge to the Meter to the B/C terminal of the gas furnace low volt- recoup cell cold header and the burner box fittings age terminal board and the other AC Volt Meter lead using field supplied tees and hoses (Figure 1.)
  • Page 151 Pressure Switches Step 4 Set the comfort control thermostat to call for heat. Connect the AC voltmeter to the pressure switch being tested, then go to Step 5. Step 5 The AC voltmeter should read 24v AC until the inducer motor comes up to speed to create the operating pressure needed to close the switch.
  • Page 152 Pressure Switches GF - C 4...
  • Page 153 Gas Valves Communicating Gas Furnaces Section D 80% Furnace Manifold Gas Pressure Measurement & Adjustment ........... 2 Adjusting Manifold Outlet Pressure ....................2 Modulating Furnace Manifold Gas Pressure Measurement & Adjustment ........4 Setting Manifold Pressure Using Contingency Mode ..............4 Setting Manifold Pressure Using Installer Test Mode ..............
  • Page 154 Gas Valves 80% Modulating Furnace Manifold Gas Pressure Measurement & Adjustment Tighten all pressure test screws loosened when ad- Figure 2 justing gas pressure. Replace both regulator cover screws. Leak check the fittings before placing the fur- nace into regular service. Failure to follow this warn- ing could result in fire, explosion, or property damage.
  • Page 155 Gas Valves Step 6 Figure 5 Adjust regulator (Figure 4) until pressure shown on manometer matches the pressure specified in Table 1. To increase outlet pressure, turn the regulator adjustment screw clockwise. To decrease outlet pressure, turn the regulator adjustment screw counterclockwise.
  • Page 156 Gas Valves Figure 7 Step 12 Turn off all electrical power to the system. Step 13 Remove the manometer and tubing and tighten the pressure tap screws. Step 14 Using a leak detection solution of soap suds, check for leaks at the pressure outlet boss and pressure tap test screw.
  • Page 157 Gas Valves Step 4 Figure 11 Let the furnace go through the Stage 1 low heat learning routine and its temperature rise stabilize. The temperature rise and learning routine will take approximately three minutes. Step 5 Read the Stage 1 low heat manifold gas pressure after the furnace’s temperature rise has stabilized.
  • Page 158 Gas Valves Step 8 Step 12 The furnace IFC will stop the low heat 50% duty heating Let the furnace go through the Stage 2 (100% high cycle after ten minutes. To manually exit the Stage 1 heat) learning routine and its temperature rise to low heat contingency cycle, remove 115 VAC power stabilize.
  • Page 159 Gas Valves Step 15 Figure 17 Replace and tighten the adjustment cover for the high heat manifold adjustment screw and then read the manifold pressure again. This procedure may need to be repeated until the manifold gas pressure is 3.5" of Water Column pressure.
  • Page 160 Gas Valves Step 20 Setting Manifold Pressure Using a leak detection solution or soap suds, check Using Installer Test Mode for leaks at plug or outlet pressure tap screw. This method can only be used when a Step 21 communicating comfort control is being used. For communicating applications, reconnect the thermostat data line to the D terminal of the furnace To adjust the manifold pressure using Installer...
  • Page 161 Gas Valves Step 8 Step 4 If needed, remove the low heat pressure adjustment Using Installer Test #3 in a dual fuel application, cover and adjust the gas valve’s low heat pressure select 3 on the right hand side of the screen using the adjustment screw to obtain the correct pressure UP arrow for low heat (Figure 21).
  • Page 162 Gas Valves Step 9 Figure 25 Once the low heat gas pressure is adjusted, use the Installer Test to select 100% (high) heat. Using Installer Test #3 in a dual fuel application, select 4 on the right hand side of the screen using the UP arrow for 100% (high) heat (Figure 24).
  • Page 163 Gas Valves Step 14 Three Stage Furnace Gas Pressure If the firing rate cannot be obtained with the manifold Measurement & Adjustment pressures specified in Table 4, check inlet gas piping See pressure test connection diagrams for hook-up for proper sizing and pressure. If insufficient, correct configuration (Figures 46 &...
  • Page 164 Gas Valves Figure 29 Figure 31 Step 6 Step 8 Read the first stage manifold gas pressure after the Once the first stage gas pressure is adjusted, turn furnace’s temperature rise has stabilized (Figure 30). the gas valve switch to the OFF position (Figure 32). Operate the furnace for two more minutes to cool down Figure 30 the heat exchanger.
  • Page 165 Gas Valves Step 14 Figure 33 Replace and tighten the dust cap for the third stage adjustment screw and then read the manifold pressure again. This procedure may need to be repeated until the manifold gas pressure is 3.5" of Water Column pressure (Figure 35).
  • Page 166 Gas Valves Figure 36 Step 20 Reconnect the thermostat data line to the D terminal of the furnace (Figure 38). Turn on the 115V power to the furnace. With the thermostat data line connected to the furnace and communications between the thermostat and the furnace reestablished, the furnace operation will now be controlled.
  • Page 167 Gas Valves • UNIT TEST and NO (NO) will now be displayed. gas valve manifold pressure measurement fitting. Use the arrow button to change the NO to a This tube and tee is in addition to the tube YES and then press ENTER. attached to the gas valve pressure tap on the outlet side of the gas valve.
  • Page 168 Gas Valves b. Scroll to the right and select “Gas Val Setup”. c. Push the Enter button. d. Select “MIN” and push the Enter button. e. When asked “Are You Sure”, select Yes, and push the Enter button. f. The furnace will now begin the ignition sequence. g.
  • Page 169 Gas Valves i. Allow 5 minutes to pass before attempting to adjust the 100% manifold pressure. This will insure that WARNING! EXPLOSION HAZARD REPLACE AND/ the learning routine is complete and that the heat OR TIGHTEN ALL PLUGS REMOVED OR rise is stable.
  • Page 170 Gas Valves Table 10 Figure 39 GF - D 18...
  • Page 171 Gas Valves Figure 40 Setting Manifold Pressure Using Installer Test Mode Step 1 If convenient, the communicating comfort control can be accessed as it is installed in the home. If not convenient, the communicating comfort control can be attached directly at the furnace for this procedure before moving it to its final installation location.
  • Page 172 Gas Valves Figure 42 Step 7 If needed, remove the first stage pressure adjustment cover and adjust the gas valve’s first stage of heat pressure adjustment screw to obtain the correct first stage pressure. (Figure 45). Use Manifold Pressure Settings Table 11 for the correct first stage pressure reading in inches of Water Column pressure.
  • Page 173 Gas Valves Table 46 Step 11 Replace and tighten the dust cap for the third stage adjustment screw and then read the manifold pressure again. This procedure may need to be repeated until the manifold gas pressure is 3.5" of Water Column (Figure 48).
  • Page 174 Gas Valves Figure 49 Figure 50 GF - D 22...
  • Page 175 Gas Valves Modulating & three stage gas valve Figure 52 solenoid check Introduction If a call for heat is present and the furnace enters a trial for ignition, the furnace control board will energize the gas valve 24 volt solenoid via the 15 pin plug located at the lower left side of the control board (Figure 51).
  • Page 176 Gas Valves Step 2 Figure 55 Start another call for heat cycle and remove the 24 volt connector plug at the gas valve (Figure 53). Figure 53 If voltage is not present between pins 11 and 13 of the 15 pin plug, replace the furnace control. Step 3 Check for 24 volts at the plug when the furnace control calls for gas valve operation (after the control has...
  • Page 177 Silicon Nitride Ignitor Communicating Gas Furnaces Section E Ignitor Learning Routine ........................2 Learning Process ........................... 2 Troubleshooting ..........................3 GF - E 1...
  • Page 178 Silicon Nitride Ignitor Ignitor Learning Routine Number of cycles per second affects the voltage or voltage R.M.S. Figure 1 R.M.S. = Root--Mean--Square = The value assigned to an alternating current or voltage that results in the same power dissipation in a fixed resistance as DC current or voltage of the same numerical value.
  • Page 179 Silicon Nitride Ignitor If for some reason flame is still not proven on this retry goes through a warm-up period and then gas valve is for ignition, the IFC will then raise the AC sine wave energized. If the ignitor fails to glow, the trial for igni- cycles four steps up (Figure 5.) tion period will fail.
  • Page 180 Silicon Nitride Ignitor GF - E 4...
  • Page 181 Measuring Flame Current Communicating Gas Furnaces Section F Introduction ............................2 Electrical circuit ..........................2 Minimum flame current level ......................3 Troubleshooting ..........................3 Causes of low flame current level ....................3 Measuring flame current with a digital multimeter ................. 4 LED flash code ..........................
  • Page 182 Measuring Flame Current Introduction Figure 3 All communicating gas furnaces use the principle of Flame Rectification to prove the presence of burner flame. The flame rod circuit consists of a flame rod assembly that is mounted at the opposite end of the burner rack from the ignitor (Figure 1.) Figure 1 Flame rod...
  • Page 183 Measuring Flame Current The AC potential creates a current flow in two direc- Troubleshooting tions. The current flow is greater in one direction than the other (Figure 5.) Causes of low flame current level Figure 5 • Dirty flame rod (Figure 7) (Clean the flame rod with metallic abrasive) •...
  • Page 184 Measuring Flame Current Step 4 Measuring flame current with a digital Set the multimeter to read DC microamperes (See multimeter Figure 12.) The procedure for measuring flame current is quite Figure 12 simple. To perform the test, you will need a digital multimeter capable of reading DC microampere cur- rent.
  • Page 185 Measuring Flame Current LED flash code The furnace control will indicate a two flash code when the furnace has locked out on flame detection. Typically, this fault code is caused by a dirty flame rod or a lack of proper inlet gas pressure (cold days when the fuel line pressure falls below the minimum level required to make the gas valve perform properly.) Natu- ral gas furnaces require a minimum of 5”...
  • Page 186 Measuring Flame Current GF - F 6...
  • Page 187 Flame Roll-Out Limit Switches Communicating Gas Furnaces Section G Purpose of the flame roll-out limit switch ..................2 Electrical circuit ..........................2 Troubleshooting ..........................3 Using ohmmeter ..........................3 Using voltmeter ..........................4 Causes of flame roll-out trips ......................4 GF - G 1...
  • Page 188 Flame Roll-Out Limit Switches Purpose of the flame roll-out limit switch Integrated furnace controls (IFC) monitor the position of limit switches during a call for heat via a connection Flame roll-out limit controls (Figure 1) protect against to a 15 pin plug (Figure 3) located on the IFC board. abnormally high temperature in the furnace burner area.
  • Page 189 Flame Roll-Out Limit Switches Step 4 Troubleshooting Resistance will be 0 ohms if the switch is closed (Figure 6.) Using ohmmeter Figure 6 Step 1 If the furnace is hot, allow it to cool down and then remove power to the furnace. Step 2 Remove the two wires from the flame roll-out switch (Figure 4.)
  • Page 190 Flame Roll-Out Limit Switches Using voltmeter Step 1 Call for heat. Step 2 Place your voltmeter leads across the limit switch terminals (Figure 9.) Figure 9 Step 3 You should measure 0 volts if the limit is closed (Fig- ure 10.) If the limit is open, you will measure 24 volts. Figure 10 Causes of flame roll-out trips •...
  • Page 191 Indoor Blower Motor Communicating Gas Furnaces Section H Variable Speed Indoor Blower Motor Operation ................2 Serial Port Communication ......................2 Go/No - Go Test for Serial Port V.S. Blower Motor ................2 Indoor Serial Port Variable Speed Blower Motor Test ..............4 GF - H 1...
  • Page 192 Indoor Blower Motor Figure 2 Variable Speed Indoor Blower Motor Operation Serial Port Communication The Serial Port Communication type of variable speed motor operates the same as the 24 volt controlled V.S. type except the on/off control and speed signals are now a digital command signal.
  • Page 193 Indoor Blower Motor Figure 3 Step 5 Does the serial port variable speed motor start and run after a short delay to turn on? Yes: Serial port variable speed motor is good. Check the furnace IFC or the air handler control board. No: Go to Step 6.
  • Page 194 Indoor Blower Motor Step 2 Indoor Serial Port Variable Speed Blower Disconnect the blower motor’s low voltage harness Motor Test from the furnace’s IFC or the air handler’s control board (Figure 8). Step 1 Is the line voltage to the blower motor high volt- Furnace IFC plug is E8.
  • Page 195 Indoor Blower Motor Figure 9 Step 4 Jumper 24 volts AC in to the blower motor low voltage plug pin #3 and pin #4 (Figure 10) The blower motor should start to run after a short delay. The blower motor should run at 75% of its programmed torque. Does the blower motor run? Yes: Repair or replace the blower low voltage harness.
  • Page 196 Indoor Blower Motor GF - H 6...
  • Page 197 Main Limit Switch Communicating Gas Furnaces Section I Introduction ............................2 Electrical circuit ..........................2 Troubleshooting ..........................3 Testing main limit operation ......................3 Electrical check of main limit switch ....................3 Causes of main limit opening during furnace operation ..............4 GF - I 1...
  • Page 198 Main Limit Switch Introduction Figure 3 Figure 1 If the main limit switch re-closes at any time, the fur- Main limit switch nace will then retry an attempt at normal furnace op- e r a t i o n . The main limit switch (Figure 1) is a normally closed Electrical circuit temperature activated switch that will open to shut down...
  • Page 199 Main Limit Switch If a limit switch opens, the diagnostic fault code indi- Figure 6 cated by the furnace control board diagnostic LED will be a flash four-sequence (Figure 5.) Figure 5 Furnace Control Board Diagnostic LED Step 4 Call for heat. All stages if the furnace is a multi-stage furnace.
  • Page 200 Main Limit Switch Step 3 Place both meter leads across the main limit electri- cal terminals (Figure 7). Figure 7 Step 4 A zero volt reading indicates a closed switch (proper condition.) Step 5 A 24-volt reading indicates the switch is open. Step 6 If the air temperature is below the switch open set- ting, yet the switch remains open, replace the switch.
  • Page 201 Alert Codes & Flowcharts Communicating Gas Furnaces Section J Alert Code Guide ..........................2 Troubleshooting flowcharts ....................... 3 Variable Speed, 2-Stage Communicating Gas Furnace .............. 3-17 Modulating Communicating Gas Furnace ................. 18-33 GF - J 1...
  • Page 202 Alert Codes & Flowcharts Alert code guide GF - J 2...
  • Page 203 Alert Codes & Flowcharts GF - J 3...
  • Page 204 Alert Codes & Flowcharts Troubleshooting Flowcharts Variable Speed, 2-Stage Communicating Gas Furnace Troubleshooting Flowchart Index - Variable Speed, 2-Stage 4) IFC Component Layout 4) LED Flash Codes 5) Getting started 6) 2 Flash Troubleshooting Retry and Recycle Lockout 7) Ignitor Positioning 8) 3 Flash Troubleshooting Pressure Switch Errors 9) 4 Flash Troubleshooting High Limit and Auxiliary Limit 10) 4 Flash Troubleshooting Roll Out Limit...
  • Page 205 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 5...
  • Page 206 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 6...
  • Page 207 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 7...
  • Page 208 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 8...
  • Page 209 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 9...
  • Page 210 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 10...
  • Page 211 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 11...
  • Page 212 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 12...
  • Page 213 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 13...
  • Page 214 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 14...
  • Page 215 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 15...
  • Page 216 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 16...
  • Page 217 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 17...
  • Page 218 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 18...
  • Page 219 Alert Codes & Flowcharts Troubleshooting Flowcharts Modulating Communicating Gas Furnace Troubleshooting Flowchart Index - Modulating Communicating Gas Furnace 19) IFC Component Layout 19) LED Flash Codes 20) Getting started 21) 2 Flash Troubleshooting Retry and Recycle Lockout 22) 3 Flash Troubleshooting Pressure Switch Errors 23) 4 Flash Troubleshooting High Limit and Auxiliary Limit 24) 4 Flash Troubleshooting Roll Out Limit 25) 5 Flash Troubleshooting Flame Error...
  • Page 220 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 20...
  • Page 221 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 21...
  • Page 222 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 22...
  • Page 223 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 23...
  • Page 224 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 24...
  • Page 225 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 25...
  • Page 226 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 26...
  • Page 227 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 27...
  • Page 228 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 28...
  • Page 229 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 29...
  • Page 230 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 30...
  • Page 231 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 31...
  • Page 232 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 32...
  • Page 233 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 33...
  • Page 234 Alert Codes & Flowcharts Troubleshooting Flowcharts GF - J 34...
  • Page 235 Electronic Air Cleaners Electronic Air Cleaners Section A Components of the Air Cleaner ........................... 2 Introduction ................................3 Modes of Operation .............................. 3 Electrical Connections ............................3 Wiring Diagram for Communicating Mode ....................4 Wiring Diagram for 24V Mode ........................5 Electrical Connections To A Communicating Systems Air Handler In Conventional 24V Mode ....

  • Page 236: Components Of The Air Cleaner

    Electronic Air Cleaners Components of the Air Cleaner WARNING CAUTION This information is for use by individuals having Reconnect All Grounding Devices. All parts of this adequate backgrounds of electrical and mechanical product that are capable of conducting electrical experience. Any attempt to repair a central air current are grounded.

  • Page 237: Introduction

    Electronic Air Cleaners Note: A 50 VA transformer is required for furnace ap- Introduction plications and 75 VA required for air handler applica- tions. If the indoor air handler already has a properly The whole house air cleaner can be installed either as sized transformer, no replacement is required.

  • Page 238: Wiring Diagram For Communicating Mode

    Electronic Air Cleaners Wiring Diagram for Communicating Mode CAUTION DO NOT attach the power/control cable to a 120 Volt EAC tap. The air cleaner uses 24 Volt power. Failure to use 24 VAC results in permanent damage to the air cleaner. •...

  • Page 239: Wiring Diagram For 24V Mode

    Electronic Air Cleaners Figure 2 Wiring Diagram for 24V Mode • Connect the power/control wiring per Figure 3. Note: Communicating furnaces require KIT # BAYACCECOMM101. Note: Wiring diagrams for the Communicating Air Handler, Communicating Furnaces and Oil Furnace can be found on pages A6-A7 of this chapter.

  • Page 240: Electrical Connections To A Communicating Systems Air Handler In Conventional 24V Mode

    Electronic Air Cleaners BAYTRANS12024 Transformer • Transformer must have a grounded 120 VAC power source. Do not defeat ground plug on the transformer. • Mount transformer to building structure with the four provided wood screws. Note: For systems order a 120 VAC to 24 VAC transformer, KIT# BAYTRANS12024 to provide 24 volt power only to the air cleaner.
  • Page 241 Electronic Air Cleaners STEP 7 Connect the green wire from the air cleaner harness to the white wire on the Communicating Systems Air Handler. STEP 8 Using the wire harness supplied with the air cleaner, connect the Red and Blue wires from the air cleaner harness to “R”...

  • Page 242: Electrical Connections To A Communicating Systems Air Handler In Communicating Mode

    Electronic Air Cleaners Electrical Connections To A Communicating Systems Air Handler In Communicating Mode WARNING Hazardous Voltage. Disconnect all electric power, including remote disconnects before servicing. Follow proper lockout/tagout procedures to ensure the power can not be inadvertently energized. Failure to discon- nect power before servicing could result in death or serious injury.

  • Page 243: Electrical Connections To A Communicating Furnace In 24V Mode

    Electronic Air Cleaners Figure/Diagram for Electrical Connections To A Communicating Systems Air Handler In Communicating Mode Electrical Connections To A Communicating Furnace in 24V Mode to the underside of the blower deck on an up-flow WARNING furnace or the 3 screws that secure the IFC platform to the top panel on a down-flow furnace.
  • Page 244 Electronic Air Cleaners STEP 7 STEP 13 Remove the EAC-H 115VAC and EAC-N wires (white Attach the black stripped wire from the air cleaner and black) out of the junction box and pull them through wiring harness directly to ground with a screw on the the grommet in the blower deck.

  • Page 245: Electrical Connections To A Communicating System Furnace

    Electronic Air Cleaners Figure/Diagram for Electrical Connections To A Communicating Furnace in 24V Mode Electrical Connections To A Communicating System Furnace WARNING STEP 2 Hazardous Voltage. Disconnect all electric power, Open blower door to upflow or downflow furnace. including remote disconnects before servicing. Fol- low proper lockout/tagout procedures to ensure the STEP 3 power can not be inadvertently energized.
  • Page 246 Electronic Air Cleaners with the air cleaner onto the IFC platform where the STEP 9 35VA transformer was previously located. Use the Attach the black stripped wire from the air cleaner sheet metal screws supplied with the air cleaner to wiring harness directly to ground with a screw in the mount the 50VA transformer.

  • Page 247: Electrical Connections To An Oil Furnace

    Electronic Air Cleaners Electrical Connections To An Oil Furnace WARNING Hazardous Voltage. Disconnect all electric power, including remote disconnects before servicing. Follow proper lockout/tagout procedures to ensure the power can not be inadvertently energized. Failure to discon- nect power before servicing could result in death or serious injury. Refer to the diagrams below for proper connections to an oil furnace.

  • Page 248: Electrical Connections For Dual Whole House Air Cleaners

    Electronic Air Cleaners Electrical Connections For Dual Whole House Air Cleaners In some instances, two whole house air cleaners can Refer to the wiring diagrams on pages A3-A13 for guid- be utilized to manage the overall system operational ance on wiring the whole house air cleaners to the static pressure.

  • Page 249: Electrical Connections For Dual Whole House Air Cleaners And Furnace In Communicating Mode

    Electronic Air Cleaners Electrical Connections For Dual Whole House Air Cleaners and Furnace In Communicating Mode AC - A 15...

  • Page 250: Display Features

    Electronic Air Cleaners In normal operation, the Air Cleaner makes a slight Display Features sound as the air passes through it and is cleaned. In Display Features some applications, you may notice this sound com- The Air Cleaner display can be used for several func- ing from the return air vent(s).

  • Page 251: Pre-Filter Settings

    Electronic Air Cleaners To change any of the settings, press the Power but- system, set all timers on both air cleaners to the same ton once. Follow the below instructions for setting the settings. The comfort control will only report one air pre-filter and collection cell timers.

  • Page 252: Fault Codes

    Electronic Air Cleaners and number of LEDs that are on indicates how the control is presently programmed. (See Set-Up Charts on previous page). To enter the Fault Codes section press and hold the Reset Button for ten seconds. Af- ter ten seconds the main LED display will go out for one second and then some of the LEDs may begin to flash on and off.
  • Page 253 Electronic Air Cleaners on and off. Compare this combination of flashing LEDs position numbers to the Fault Code chart to see which fault has been detected. The number one Yellow LED will always be out in the Fault Code report section. Dual Air Cleaner Faults and Filter Reset: When dual air cleaners are installed as part of a communicating system, each whole house air cleaner will retain its own faults.
  • Page 254 Electronic Air Cleaners Display Fault LED Codes Table AC - A 20...

  • Page 255: Cleaning

    Electronic Air Cleaners To clear all three faults codes from the control’s Step 1 Turn the air conditioning system off at the Comfort memory, press and hold the Reset button for 2-4 sec- onds when the fault codes are displayed. When the Control (thermostat).

  • Page 256: Vacuum Cleaning

    Electronic Air Cleaners conditions in the home (pets, smokers, etc.). Please Step 5 see “Set-Up Mode” (page A16) to change the factory Remove the Pre-Filter (Figure 11) and/or the Collec- settings. tion Cells (Figure 12) from the Air Cleaner. Step 1 Using a vacuum hose, vacuum in even strokes across the entire Pre-Filter.
  • Page 257 Electronic Air Cleaners the entire Collection Cells. Vacuum using even strokes Step 2 Reinstall the Collection Cells into the Air Cleaner. in one direction, then repeat the process using even strokes in the opposite direction, as demonstrated in Ensure the handles on both of the Collection Cells are folded flat.
  • Page 258 Electronic Air Cleaners tal conditions, like tobacco smoke, cause the Collec- Step 1 tion Cells to need to be washed with water. Washing If the Collection Cells do have the “200/200-1” mark the Collection Cells is acceptable ONLY if the Collec- on them, they may be washed using a low pressure tion Cells have a “200/200-1”...
  • Page 259 Electronic Air Cleaners Note: The Pre-Filter may also be washed only if the Collection Cells show a "200/200-1". Follow the same instructions to wash the PRE-FILTER - being sure to tap gently and wipe off any visible water droplets. Reset Timers To reset the Pre-Filter timer, press and hold the Reset button until the Pre-Filter LED turns off.
  • Page 260 Electronic Air Cleaners assemble the Field Charger. a Screwdriver, Jumper Wire with Alligator Clips on each end, tape and dry paper. Step 5 Push a block of styrofoam down over the Field Charger Testing With A High Voltage Probe Pin. Step 1 Turn off the Air Cleaner and remove the Power Door.
  • Page 261 Electronic Air Cleaners first Green LED should be on and then start flashing Step 3 after the time delay to 'on' has expired. The Air Cleaner Tape a piece of paper to a screwdriver blade with ½ has to have a call for operation for the first Green LED inch of the paper sticking out in front of the blade.

  • Page 262: Pressure Drop

    Electronic Air Cleaners Set-Up mode. The first Green LED will be on and it Step 9 will start flashing after the first 10 [12] minutes of If the arc occurred when the end of the paper was indoor fan operation. The Air Cleaner has to have a near or touching the Power Door High Voltage call for operation for the first Green LED to flash on terminal during this test, the Power Door assembly...

  • Page 263: Led Troubleshooting

    Electronic Air Cleaners LED Troubleshooting Service Indications Service Checks Indoor Blower On/ 1. Check that the Power Door is installed correctly Air Cleaner First Green LED Off and the latches closed. The actuator tab must engage the door safety switch. 2.

  • Page 264: Component Failure Evaluation

    Electronic Air Cleaners Flows Charts Component Failure Evaluation AC - A 30...

  • Page 265: Component Failure Evaluation In 24 Volt Mode

    Electronic Air Cleaners Component Failure Evaluation in 24 Volt Mode AC - A 31...

  • Page 266: Component Failure Evaluation In Communicating Mode

    Electronic Air Cleaners Component Failure Evaluation in Communicating Mode AC - A 32...
  • Page 267 Alert Code Response Communicating Systems Reference Section A Charge Assist Control Board ..........................3 Summary of Alert Code & Charge Assist LEDS ..................3 Flash Rate Summary ............................4 Communicating systems troubleshooting guide ....................5 Wait ................................. 5 Error 10: Ignition means fault ......................... 5 Error 18: Control failure ..........................
  • Page 268 Alert Code Response Fuse failure ..............................22 PM bad or missing ............................22 Temperature sensor failure .......................... 23 Demand configuration fault .......................... 23 Air handler fault LED’s ............................23 Air handler fault LED - Solid ON ........................23 Air handler fault LED - 2 flash ........................23 Air handler fault LED - 3 flash ........................
  • Page 269 Alert Code Response Summary of Alert Code & Charge Assist LEDS R - A 3...
  • Page 270 Alert Code Response Flash Rate Summary R - A 4...

  • Page 271: Communicating Systems Troubleshooting Guide

    Alert Code Response Error 10: Ignition means fault Communicating systems troubleshooting guide Comfort Control = Err 10 Wait User Interface = IGNITER ERR Furnace Fault LED = 6 Flash Comfort Control = Wait User Interface = No Alert Displayed Problem Description Outdoor Unit Fault LED = 7 Flash •...

  • Page 272: Error 22: Soft Lock-Out Due To Flame Loss Or Ignition Retries

    Alert Code Response Error 22: Soft lock-out due to flame loss or Error 18: Control failure ignition retries Comfort Control = Err 18 User Interface = No Alert Displayed Comfort Control = Err 22 Outdoor Unit Fault LED = 18 Flash User Interface = RECYCLE LO Furnace Fault LED = 2 Flash Problem Description...
  • Page 273 Alert Code Response Error 27: Replace device Error 26: Temperature limit fault Comfort Control = Err 27 Comfort Control = Err 26 User Interface = No Alert Displayed User Interface = AUX LIMIT Air Handler Fault LED = No Fault Reported Furnace Fault LED = 4 Flash Furnace Fault LED = No Fault Reported Problem Description...

  • Page 274: Error 53: Outdoor Sensor Missing

    Alert Code Response Error 64: Stuck button(s) Error 53: Outdoor sensor missing Comfort Control = Err 64 Comfort Control = Err 53 User Interface = No Alert Displayed User Interface = No Alert Displayed Air Cleaner Fault LED = YEL-1, 2 & 3 ON Outdoor Fault LED = No Fault Displayed RED-1 &...
  • Page 275 Alert Code Response Error 67: Temperature sensor fault Error 80: High pressure monitor fault Comfort Control = Err 67 Comfort Control = Err 80 User Interface = No Alert Displayed User Interface = No Alert Displayed Outdoor Fault LED = 6 Flash Outdoor Fault LED = 17 Flash Problem Description Problem Description...

  • Page 276: Error 89: Equipment Missing

    Alert Code Response Error 89: Equipment missing Error 90: Communication busy fault Comfort Control = Err 89 Comfort Control = Err 90 User Interface = No Alert Displayed User Interface = No Alert Displayed Outdoor Fault LED = No Fault Reported Fault LED = No Fault Reported by Indoor or Outdoor Unit Problem Description Problem Description...
  • Page 277 Alert Code Response Error 91: Communication fault Error 91: Communication fault Comfort Control = Err 91 Comfort Control = Err 91 User Interface = BLW COMM ERR User Interface = SYS COMM ERR Air Handler Fault LED = 3 Flash Air Handler Fault LED = 3 Flash Furnace Fault LED = 10 Flash Furnace Fault LED = 10 Flash...

  • Page 278: Error 93: Gas Valve Fault

    Alert Code Response Error 91: Communication fault Error 91: Communication fault Comfort Control = Err 91 Comfort Control = Err 91 User Interface = No Alert Displayed User Interface = IND COMM ERR Outdoor Unit Fault LED = 1 Flash Furnace Fault LED = 10 Flash Indoor Unit Fault LED = No Fault Reported Problem Description...

  • Page 279: Error 101: Y1 Relay Fault

    Alert Code Response Error 93: Gas valve fault Error 101: Y1 relay fault Comfort Control = Err 93 Comfort Control = Err 101 User Interface = INT GV ERR User Interface = Y1 ON ERR Furnace Fault LED = Solid ON Air Handler Fault LED = 7 Flash Problem Description Furnace Fault LED = No Fault Reported...

  • Page 280: Error 105: Heater Interlock Relay Fault

    Alert Code Response Error 104: Heater relay fault Error 105: Heater interlock relay fault Comfort Control = Err 104 Comfort Control = Err 105 User Interface = HT ON ERR User Interface = INTLK ON ERR Air Handler Fault LED = 4 Flash Air Handler Fault LED = 4 Flash Problem Description Problem Description...

  • Page 281: Error 107: Repetitive Arcing

    Alert Code Response Error 107: Repetitive arcing Error 108: HV output fault Comfort Control = Err 107 Comfort Control = Err 108 User Interface = No Alert Displayed User Interface = No Alert Displayed Air Cleaner Fault LED = YEL-2, 3 & 4 ON Air Cleaner Fault LED = YEL-2 ON, 3 &...

  • Page 282: Error 113: Liquid Pressure Sensor Fault

    Alert Code Response Error 109: Input current fault Error 114: PM bad or missing Comfort Control = Err 109 Comfort Control = Err 114 User Interface = No Alert Displayed User Interface = PM MEM ERR Air Cleaner Fault LED = YEL-2 & 3 ON, 4 OFF Air Handler Fault LED = 2 Flash RED-1, 2 &...

  • Page 283: Error 125: Input Ac Voltage Fault

    Alert Code Response Error 114: PM bad or missing Error 114: PM bad or missing Comfort Control = Err 114 Comfort Control = Err 114 User Interface = ID MTR ERR User Interface = No Alert Displayed Air Handler Fault LED = 2 Flash Outdoor Unit Fault LED = 14 Flash Furnace Fault LED = No Fault Reported Problem Description...

  • Page 284: Error 126: Equipment Change Alert

    Alert Code Response Miscellaneous alert codes Error 126: Equipment change alert Pressure switch failure Comfort Control = Err 126 User Interface = No Alert Displayed Outdoor Unit Fault LED = No Fault Reported Comfort Control = No Error Code Displayed User Interface = PS1 OPEN Problem Description Furnace Fault LED = 3 Flash...

  • Page 285: Low Flame Signal

    Alert Code Response Pressure switch failure Low flame signal Comfort Control = No Error Code Displayed Comfort Control = No Error Code Displayed User Interface = PS2 CLOSED User Interface = LO FLAME SNS Furnace Fault LED = 3 Flash Furnace Fault LED = 8 Flash Problem Description Problem Description...

  • Page 286: Flame Lost Or Ignition Failed

    Alert Code Response Flame lost or ignition failed Line polarity fault Comfort Control = No Error Code Displayed Comfort Control = No Error Code Displayed User Interface = RECYCLE User Interface = POLARITY ERR Furnace Fault LED = 2 Flash Furnace Fault LED = 6 Flash Problem Description Problem Description...

  • Page 287: Ground Fault

    Alert Code Response Communication busy fault Ground fault Comfort Control = No Error Code Displayed Comfort Control = No Error Code Displayed User Interface = IND COMM CRC User Interface = GND FAULT Furnace Fault LED = 6 Flash Furnace Fault LED = 10 Flash Problem Description Problem Description •...

  • Page 288: Fuse Failure

    Alert Code Response Fuse failure PM bad or missing Comfort Control = No Error Code Displayed Comfort Control = No Error Code Displayed User Interface = CHECK FUSE User Interface = CAP MISMATCH Air Handler Fault LED = Solid ON Air Handler Fault LED = 2 Flash Furnace Fault LED = No Fault Reported Furnace Fault LED = No Fault Reported...

  • Page 289: Temperature Sensor Failure

    Alert Code Response Temperature sensor failure Demand configuration fault Comfort Control = No Error Code Displayed Comfort Control = No Error Code Displayed User Interface = TS1 SHORT User Interface = HT CFG ERR Air Handler Fault LED = No Fault Reported Air Handler Fault LED = 9 Fault Furnace Fault LED = No Fault Reported Problem Description...
  • Page 290 Alert Code Response Air handler fault LED - 3 Flash Furnace fault LED - 3 Flash User Interface: Comfort Control: Comfort Control: User Interface: - SYS COMM CRC - No Error Code Displayed - No Error Code Displayed - PS1 OPEN - BLW COMM CRC - PS2 OPEN - PS3 OPEN...

  • Page 291: Outdoor Unit Fault Led's

    Alert Code Response Outdoor unit fault LED’s Outdoor unit fault LED 4 flash Comfort Control = No Error Code Displayed Outdoor unit fault LED 1 Flash User Interface = No Alert Displayed Comfort Control: Problem Description - Err 90 • Defrost Fault A and (B and/or C) - 60 or more A faults and one or more B faults Comfort Control: User Interface:...

  • Page 292: Outdoor Unit Fault Led 11 Flash

    Alert Code Response Outdoor unit fault LED 11 flash Outdoor unit fault LED 13 flash Comfort Control = No Error Code Displayed Comfort Control = No Error Code Displayed User Interface = No Alert Displayed User Interface = No Alert Displayed Problem Description Problem Description •...

  • Page 293: Eev Fault Led 1 Flash

    Alert Code Response EEV fault LED 1 flash EEV fault LED 6 flash Problem Description Problem Description • EEV stepper motor coil fault • EEV is not responding to a request for position change Possible Causes/Solutions Possible Causes/Solutions • EEV is stuck •...
  • Page 294 Alert Code Response R - A 28...
  • Page 295 Solving Err 91 Comm Errors Communicating Systems Reference Section B Err 91 displayed at the Comfort Control .................... 2 When Err 91 is displayed at the Comfort Control, thermostat will go to OFF ........2 Troubleshooting Err 91 displayed at the Comfort Control ............... 3 Troubleshooting IND COMM ERR ......................

  • Page 296: Err 91 Displayed At The Comfort Control

    Solving Err 91 Comm Errors Err 91 displayed at the Comfort Control If the COM LED is flashing slowly in groups of 2, 3, 4, or 5, see Troubleshooting Chart ERR 91 dis- When Err 91 is displayed at the Comfort Control, played at the Comfort Control.

  • Page 297: Troubleshooting Err 91 Displayed At The Comfort Control

    Solving Err 91 Comm Errors Troubleshooting Err 91 displayed at the and the pin in plug E8. Is the voltage correct? Comfort Control Yes: If the 12 volts DC is present at both pins in Step 1 plug E8, the fault is with the harness or the indoor At the User Interface Assembly, scroll down ...

  • Page 298: Inducer Motor Drive Board Led Functions

    Solving Err 91 Comm Errors Troubleshooting Chart IND COMM ERR No: Go to Step 7. Inducer motor drive board LED functions Step 2 Turn power ON. If the green COM LED on the inducer motor drive board is flashing, this is an indication that the inducer Is there 120 VAC at the inducer motor drive board motor drive board and the gas furnace IFC are com- terminal L1 and L2? (See Figure 5.)
  • Page 299 Solving Err 91 Comm Errors Figure 7 Figure 6 Yes: Go to Step 5. Step 5 No: Go to Step 4. De-power the gas furnace. At the gas furnace IFC< remove the wire from the terminal RX at the E9 plug Step 4 going to the inducer motor drive.
  • Page 300 Solving Err 91 Comm Errors Detail 2: Connect a digital DC voltmeter to the RX Is there DC voltage between the inducer motor wire removed from E9 plug and the B/C low voltage drive board terminal TX and GND? (See Figure terminal board.
  • Page 301 Solving Err 91 Comm Errors Figure 11 Yes: Go to Step 2. No: Go to Step 7. Note: The colors of the low voltage V.S. blower motor wires are: Gas furnace uses a blue wire and a black wire. Air handler uses a blue wire and a brown wire. Step 2 Is there 120 VAC at the indoor blower high voltage plug terminals? (See Figure 13.)
  • Page 302 Solving Err 91 Comm Errors Figure 14 Figure 15b This DC voltage should be going up and down between 0.50 volts DC and 1.07 volts DC. The voltmeter will stop reading at times and then start reading again. Yes: Go to Step 5. No: Go to Step 4.
  • Page 303 Solving Err 91 Comm Errors Figure 16 Figure 17b Detail 2: Connect a digital DC voltmeter to the RX wire removed from the low voltage plug and the B/C terminal at the low voltage terminal board. Detail 3: Re-power the gas furnace. Is there DC voltage between the wire removed Yes: Replace the gas furnace IFC or the air handler from the gas furnace IFC or the air handler control...

  • Page 304: System Communication Troubleshooting

    Solving Err 91 Comm Errors This DC voltage should be going up and down Figure 19b between 0.152 volts DC and 0.174 volts DC. The voltage meter will stop reading at times and then start reading again. Yes: Repair or replace the low voltage harness going from the indoor blower to the gas furnace IFC.
  • Page 305 Solving Err 91 Comm Errors Note: If there is no 24 volts AC power at some of the The furnace IFC or air handler count as one, the communicating components, the BM LED may be thermostat counts as two, the outdoor unit counts as very dim or out, or may be flashing very fast.
  • Page 306 Solving Err 91 Comm Errors If BLW COMM ERR is displayed (Figure 22), go to the No: Repair or replace the thermostat wire. Troubleshooting BLW COMM ERR section. Figure 24 Figure 22 BLW COMM ERR If NO ALERTS is displayed (See Figure 23), go to Step 9.
  • Page 307 Solving Err 91 Comm Errors Does the comfort sensor and furnace IFC or air former. Repair or replace as needed. handler now communicate? Figure 27 Yes: Err 91 is being caused by the thermostat wire or its routing. Repair, reroute or replace the thermostat wire.

  • Page 308: Communicating System Voltage Readings

    Solving Err 91 Comm Errors Figure 28 Step 12 Go to the component that is being fed by the thermostat wire that was determined to be creating the ERR or fault in Step 11 and disconnect the thermostat wire going to that component. Now go back to the furnace or air handler and reconnect the thermostat wire that was determined in Step 11 to be the circuit causing the problem.

  • Page 309: Voltage Readings Made At The Furnace Or Air Handler Lvtb

    Solving Err 91 Comm Errors Voltage readings made at the furnace or air Note: The TX may have a voltage of 0.5 to 1.5 volts handler LVTB DC when air handler control board is first powered up. This may also occur if the blower motor and air R to B = 0 volts AC - With 24 volts AC to control handler control board are not communicating with board and fuse is OK, change control board.
  • Page 310 Solving Err 91 Comm Errors R - B 16...
  • Page 311 Reference Materials Communicating Systems Reference Section C Field Wiring Diagrams ..........................3 Communicating Controller with Communicating Outdoor & Indoor Unit ..........3 Communicating Controller with Communicating Indoor Unit & Single Stage AC Outdoor Unit ......................4 24 Volt Thermostat with Communicating Outdoor Unit & 24V Harness Kit #BAYACHP024A ....5 Three-Stage Gas Furnace ..........................
  • Page 312 Reference Materials 16 Seer Update ............................ 23 Control Board Point Release ......................23 Summary of Issue - 16 Seer COMSYS ....................23 16 SEER Update - Control Board Point Release .................. 23 Field Actions - 16 SEER COMSYS ...................... 24 Recap - 16 SEER COMSYS ........................

  • Page 313: Field Wiring Diagrams

    Reference Materials Field Wiring Diagrams Communicating Controller with Communicating Outdoor & Indoor Unit R - C 3...

  • Page 314: Communicating Controller With Communicating Indoor Unit & Single Stage Ac Outdoor Unit

    Reference Materials Field Wiring Diagrams Communicating Controller with Communicating Indoor Unit & Single Stage AC Outdoor Unit R - C 4...

  • Page 315: 24 Volt Thermostat With Communicating Outdoor Unit & 24V Harness Kit #Bayachp024A

    Field Wiring Diagrams Reference Materials 24 Volt Thermostat with Communicating Outdoor Unit & 24V Harness Kit #BAYACHP024A R - C 5...
  • Page 316 Reference Materials Field Wiring Diagrams For instructions, components and diagrams used in Table 1 this kit, order kit #BAYACHP024A. Shown here is an excerpt from the kit for reference: Step 1 Be certain power to unit is DISCONNECTED. Step 2 Step 5 Remove cover panel on control box compartment.
  • Page 317 Reference Materials Three-Stage Gas Furnaces Vent Length Table for Variable Speed Vent Motor Models Only R - C 7...

  • Page 318: Three-Stage Gas Furnace

    Reference Materials Three-Stage Gas Furnace Pressure Switches And Interconnecting Hose Diagrams There is an orifice installed in the black tee. This tee The closing negative pressure, in inches of water & orifice assembly is connected to the black side of column, is printed on the switch label.

  • Page 319: Multi Stage Automatic Gas Valve

    Reference Materials Three-Stage Gas Furnaces Multi Stage Automatic Gas Valve The gas furnace manifold gas pressure is modulated in steps by the pressure difference of the positive inlet burner air pressure and the negative outlet air pressure of the recuperative cell. These two pressures are connected to the gas valve.

  • Page 320: Gas Furnace

    Reference Materials Gas Furnaces Pressure Switch Matrix Chart R - C 10...

  • Page 321: Communicating Systems Troubleshooting Checklist

    Reference Materials Gas Furnaces Communicating Systems Troubleshooting Checklist Note: Alert, ERR, Codes will only be displayed at the thermostat when a call for heat is being sent by the thermostat. The Red LED will be ON at the thermostat. The Furnace IFC Status LED will be flashing fast; the Fault LED will be flashing a fault code.
  • Page 322 Reference Materials Gas Furnaces R - C 12...

  • Page 323: Alert Code Guide

    Reference Materials Gas Furnaces Alert Code Guide R - C 13...

  • Page 324: User Interface Assembly

    Reference Materials User Interface Assembly Introduction The indoor User Interface Assembly will display the model and serial number during normal unit operation. In addition, the following information can also be accessed through the display. • The Units Model & Serial Number (Normal Display) •...

  • Page 325: User Interface Menu

    Reference Materials User Interface Assembly User Interface Menu R - C 15...

  • Page 326: Outdoor Sensors

    Reference Materials Outdoor Sensors Ambient Sensor & Coil Sensor R - C 16...

  • Page 327: Liquid Line Sensor

    Reference Materials Outdoor Sensors Liquid Line Sensor Liquid Line Pressure Transducer R - C 17...

  • Page 328: External Accessory Temperature Sensor Baysen01Atempa

    Reference Materials Outdoor Sensors External Accessory Temperature Sensor BAYSEN01ATEMPA R - C 18...

  • Page 329: Software Change History

    Reference Materials Software Change History - Add “Are You Sure” to Comfort Control COMSYS Air Handler Update Mode Options COMM or 24VAC  Control Board Found in User Interface  - Add “SW REV NUMBER CR34” • COMSYS Launch (1/08) CNT04962 - Found in User Interface •...

  • Page 330: Airflow (Lower Than Expected)

    Reference Materials • Service Bulletin SSA-SVB09A-EN issued • Parts disposition - Southaven 11/9/2009 • Global Parts building a supply of CNT06039 Stock up with CNT06352  Purge all stock of CNT06039 • For product applied in 24v, process replacement  control under warranty until bulletin instructions are (Complete with NLA notes) published (9214****V to 9434****V only)

  • Page 331: Re-Flashed Air Handler Motor

    Reference Materials • Corrective Action - Not a functional issue, not reported to - Personality Module change out customer - Replacement PM programming at Tyler • Close Valve Test facility - If unit pumps down, LPCO will open - Communication and shipments to - System becomes locked-out field (9/11/09) - Requires energizing the SOV to equalize...

  • Page 332: Charge Assist Control Board

    Reference Materials Charge Assist Control Board • Owner’s Guide - 22-5211-02 (Trane) • Change from CNT05127 to CNT06103 - 12-5046-02 (AmStd) - Production starts 3/22/10 FW13 • Heating setpoint range; low limit = 50º F • Change High Pressure Monitor routine (was 40º...

  • Page 333: Control Board

    • Reference Materials Control Board 16 Seer Update • 3-Stage Furnace (*UH3/*DH3) Control Board Point Release - CNT04829 • CNT04880 to CNT06042 • LAST 4 FAULTS (User Interface) - 2-5 ton 16 SEER-COMSYS models only - Add position identifier - Defrost Control enhancements Start Date (November 9th, 2009) ...
  • Page 334 Reference Materials Field Actions - 16 SEER COMSYS - New units after 9465****F are built with CNT06042 • Replacement board needs (CNT06042 only) Order High Temperature Termination - Installed units that need replacement PM when required board with high termination temp •...
  • Page 335 Reference Materials • New D.A. Part CNT06058 - Resolves ALL blank/dim display issues - Beginning with production date codes: Vidalia 10451****V  Trenton 10411****G Telephone Access Module  (80% and 95% Modulating) • Global Parts • All phase 1 TAM’s built until 0836 - Inventory in place 10/25/2010 - BAYTAM00AC00UA - Superseded in CATS &...
  • Page 336 Reference Materials R - C 26...

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