Carrier 58MVP Troubleshooting Manual
Carrier 58MVP Troubleshooting Manual

Carrier 58MVP Troubleshooting Manual

Variable-speed 2-stage electronic condensing furnace

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NOTE: Read the entire instruction manual before starting the
installation.
SAFETY CONSIDERATIONS
INDEX
Instructions .....................................................................................1
Example ..........................................................................................2
Sequence of Operation................................................................1-5
Self-Test Mode..........................................................................2
Heating Mode............................................................................2
Heating Mode-Two Stage.........................................................2
Emergency Heat Mode..........................................................2-3
Cooling Mode ...........................................................................3
Heat Pump Mode...................................................................3-4
Continuous Fan Mode ..............................................................4
Component Test.....................................................................4-5
Bypass Humidifier Mode..........................................................5
Dehumidification Mode ............................................................5
Zone Mode ................................................................................5
Start Here........................................................................................6
Service Label/Fault Code Instructions .......................................7-8
Improper Operation With No Flashing Fault Code ......................9
Not Enough Cooling Airflow ......................................................10
High-Fire Temperature Rise Too Low (Cold Blow) ..................11
LEDs 1, 2, 3, or 4 On Solid...................................................11-12
RED LED2 Flashing ....................................................................12
Fault Code 11—No Fault in Recent History Display ................13
Fault Code 12—Blower Calibration Lockout........................13-15
Fault Code 13—Limit Switch Lockout..................................15-16
Fault Code 14—Ignition Lockout................................................17
Fault Code 21—Invalid Model Selection....................................17
Fault Code 22—Set Up Error......................................................18
Fault Code 23—Invalid Blower Airflow Selection ....................18
Fault Code 24—Secondary Voltage Fuse Is Open................19-20
Fault Code 31—High-Pressure Switch Fault.........................21-22
Fault Code 32—Low-Pressure Switch Fault .........................23-24
Fault Code 33—Limit Switch Fault.......................................24-25
Fault Code 34—Ignition Proving Fault .................................26-27
Fault Code 41—Blower Outside Valid Speed Range ...........27-28
Fault Code 42—Inducer Outside Valid Speed Range...........29-30
Fault Code 43—Pressure Switch Calibration Fault...............30-31
Fault Code 44—Blower Calibration Fault ..................................32
Cleanup and Start-Up Instructions ..............................................33
APPENDIX A—Board Layout & Wiring Schematic ...........34-35
APPENDIX B—Isolation Circuits ..............................................36
APPENDIX C—Pressure Check Diagram ..................................36
APPENDIX D—Quick Motor Test Procedure ......................37-39
APPENDIX E—Variable-Speed Condensing Furnace Duct Static
and Blower Operation.............................................................40-44
APPENDIX F—Quick Reference Information ...........................45
APPENDIX G—Thermostat Staging Algorithm ...................46-47
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 101
Catalog No. 535-754
Tab 6a 8a

Troubleshooting Guide

PAGE
Printed in U.S.A.
Variable-Speed 2-Stage
Electronic Condensing Furnace
INSTRUCTIONS
This guide uses your expertise and observations to lead you to the
trouble spot as efficiently as possible. This is only intended as a
guide and should not be used blindly. Your experience and
expertise are of high value when troubleshooting this unit. Do not
disregard all of your instincts.
The microprocessor furnace control was designed with diagnostic
capabilities built in. LEDs are used to flash a fault code which will
lead you to 1 of the subsections as listed in the Index.
You should ALWAYS begin in the START HERE subsection
(see Index for page number) which will guide you to the
appropriate subsection where a minimal number of steps will be
used to correct the problem. If you are very experienced at how
this furnace operates and you suspect the problem is either the
blower motor, inducer motor, or furnace control board, you can use
the quick motor test procedure at the end of the troubleshooting
guide to isolate the problem or direct you to appropriate section in
main troubleshooting guide.
Once in a subsection, read the statement or question. A statement
will have a number in the "GO TO" column. Do whatever the
statement says, then proceed to step indicated in the "GO TO"
column.
If the step is a question (a question will have a number in the
"YES" or "NO" column), answer it "YES" or "NO." If the answer
is "YES," go to step indicated in "YES" column. If the answer is
"NO," go to step indicated in "NO" column.
Let's try our guide out using the EXAMPLE section below, and
see how it works. Suppose that the problem is a defective
low-pressure switch (for example will not make). This is an
internal problem and cannot simply be seen. We go to the START
HERE section to Step 1.
Additional Service Tools are available for current variable speed
condensing furnaces. The Advanced Product Monitor Kit
KGAFP0101APM includes a harness and diskette that allows
communication with the control board through a personal com-
puter (RS-485 adapter required). The ICM Motor Simulator Kit
KGASD0101FMS is a plug-in device to help trooubleshoot ICM
inducer and blower motors and control boards. Reference price
pages for current kit numbers.
SEQUENCE OF OPERATION
Furnace control must be grounded for proper operation, or
control will lock out. Control is grounded through green wire
routed to gas valve and burner box screw.
Using schematic diagram (see Appendix A), follow sequence of
operation through different modes. This furnace has a new control
system. Read and follow wiring diagram carefully.
NOTE: If 115-v power supply to furnace or blower access panel
switch is interrupted during a call for heat, blower operates at
low-heat speed for 60 sec when power is restored before heating
cycle is resumed.
Form 58MVP-8SM
Pg 1
58MVP
9-99
Replaces: 58MVP-6SM

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Summary of Contents for Carrier 58MVP

  • Page 1: Troubleshooting Guide

    Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. Book 1 4 PC 101 Catalog No. 535-754 Printed in U.S.A. Form 58MVP-8SM Pg 1 9-99 Replaces: 58MVP-6SM Tab 6a 8a...
  • Page 2: Modes

    EXAMPLE Start Here Section STEP ACTION GO TO Step 1 tells us to record status of LEDs 1-4 and go to Step 2. — — Step 2 asks the question, "Are any LEDs flashing?". If low-pressure switch was defective, a low- —...
  • Page 3: Modes

    In emergency heat mode, the normal heat mode outlined in 4. Cooling unit—The cooling unit stops when thermostat R-Y Heating Mode section is not followed. The following sequence signal is terminated. will occur: 5. Blower off delay—When thermostat is satisfied, the R-Y/Y2 When thermostat calls for heat, the R-W/W-1 circuits close.
  • Page 4: Continuous Fan Mode

    DE CONNECTION WITHOUT DE WITH DE CONNECTION CONNECTION A98293 Fig. 1—Variable Speed Furnace Control b. R-W/W1 with R-Y/Y2 and R-G signals terminated— for cooling (R-Y/Y2) is terminated, the blower remains The blower continues to operate completing a normal operating at cooling speed for 90 sec before resuming con- blower off delay.
  • Page 5: Bypass Humidifier Mode

    When items 1-5 have been completed, the following will occur: standard humidistat to do dehumidification since the contacts open on high humidity, thus removing the 24-v signal to initiate 1. The control center goes through a brief self test. This self test dehumidification.
  • Page 6: Start Here

    START HERE—If a problem exists, the service technician should always begin troubleshooting here. STEP ACTION GO TO Remove furnace door first. DO NOT REMOVE BLOWER ACCESS PANEL! Record status of LED’s — — 1-4. See Service Label/Fault Code Instructions (Fig.4). Are any LEDs flashing? —...
  • Page 7 SERVICE STATUS LED CODE RED LED1 ON Furnace is operating in emergency heat. RED LED2 ON The microprocessor has malfunctioned. To reset: Put setup switch "SW-1" in the "ON" position and jumper thermostat terminals "R", "W/W1", and "Y/Y2" simultaneously with the door switch pushed in and power to the unit "ON".
  • Page 8: Component Test

    34 IGNITION PROVING FAULT - Control will try three more times before a lockout #14 occurs. Check for: - Gas valve defective or gas valve turned "OFF". - Defective Hot Surface Ignitor - Manual valve shut-off. - Low inlet gas pressure - Flame sensor must be ungrounded.
  • Page 9: Improper Operation With No Flashing Fault Code

    IMPROPER OPERATION WITH NO FLASHING FAULT CODE—Generally, this indicates there is no power to furnace control board. STEP ACTION GO TO Make sure power is on. — — Remove blower access panel and depress door switch. Use a piece of tape to hold switch closed. —...
  • Page 10: Not Enough Cooling Airflow

    NOT ENOUGH COOLING AIRFLOW—Generally, this indicates the Y/Y2 thermostat lead is not properly connected. STEP ACTION GO TO Remove blower access panel and depress door switch. Use a piece of tape to hold switch closed. — — Wait a few sec for self test before proceeding to next step. Make sure thermostat is calling for cooling.
  • Page 11 HIGH-FIRE TEMPERATURE TOO LOW—Generally, this indicates the HIGH/LOW solenoid in gas valve GV has failed or furnace is extremely underfired. STEP ACTION GO TO Turn power off and remove blower access panel. Make sure thermostat is NOT calling for heat. —...
  • Page 12: Red Led2 Flashing

    Put setup switch SW-1 back in OFF position. — — Jumper R and W/W1 thermostat terminals. — — Does RED LED2 turn back ON? — Install isolation relays in the W/W1 and Y/Y2 circuits per Fig. 5 in Appendix B or replace thermostat. —...
  • Page 13: Code 12 Blower Calibration Lockout

    Fault Code 11 NO FAULT IN RECENT HISTORY DISPLAY—This indicates 1 of the following: • No faults have occurred in the last 5 previous cycles and setup switch SW-1 is in ON position. • The fault history can be cleared by jumpering R, W/W1, and Y/Y2 thermostat leads simultaneously while setup switch SW-1 is in ON position.
  • Page 14 You have an open wire or bad terminal on either the ORANGE or VIOLET wire between connectors — — PL13 and PL3. Repair it or replace blower harness(es). Remove tape from door switch and turn power off at main disconnect. —...
  • Page 15: Code 13 Limit Switch Lockout

    Wait at least 5 minutes after disconnecting line voltage from equipment before opening blower motor to prevent electric shock which can cause personal injury or death. Remove tape from door switch and turn power off at main disconnect. — — Disconnect PL10 from blower assembly.
  • Page 16 Does the installation have a bypass humidifier? — Is setup switch SW-3 in ON position? — Put setup switch SW-3 in ON position. — — Cycle furnace with blower access panel in place and record temperature rise across furnace 6 min- —...
  • Page 17: Code 21 Invalid Model Selection

    Fault Code 14 IGNITION LOCKOUT—This fault indicates the system failed to ignite gas and prove flame in 4 attempts. Control will auto-reset in 3 hr. This fault could also indicate the gas valve relay GVR on furnace control board is stuck closed or there is a miswire/short to gas valve wiring. STEP ACTION GO TO...
  • Page 18: Fault Code 22-Set Up Error

    Fault Code 22 SETUP ERROR—This fault indicates that setup switches SW-1 or SW-6 are ON when they should be OFF. The following combinations will cause the fault: • Thermostat call with SW-1 ON. • Thermostat call with SW-6 ON. • SW-1 and SW-6 both ON together. STEP ACTION GO TO...
  • Page 19: Code 24 Secondary Voltage Fuse Is Open

    Table 2—Air Conditioning (A/C) Airflow Setup Switch Position A/C SWITCH POSITION ALLOWABLE FURNACE MODEL SETUP AIR CONDITIONER AIRFLOW (TONS) (CFM) A/C-1 A/C-2 A/C-3 3 Tons 3 Tons 3 Tons 5 Tons 5 Tons 5 Tons 1200 or Default 2000 1200 CFM 1200 CFM 1200 CFM 2000 CFM...
  • Page 20 Do you have continuity between the N.O. (Normally Open) contact on low-pressure switch LPS and — chassis ground? The ORANGE wire from low-pressure switch LPS is shorting to ground. Replace or repair it. — — Does Fault Code 24 occur when gas valve GV is energized? —...
  • Page 21: Fault Code 31-High-Pressure Switch Fault

    Fault Code 31 HIGH-PRESSURE SWITCH FAULT—This fault can occur under the scenarios shown below, keep in mind that whenever furnace control board shuts unit down, gas shuts off immediately, inducer continues running for 15 sec, and if blower is running, it remains running at low-heat speed or reduces to low-heat speed for selected off delay.
  • Page 22 Connect 1 side of a slope manometer with a tee to collector box pressure tap. Connect other side — — with a tee to gas valve air pressure fitting. Refer to pressure check diagram in Appendix C. Turn power on and wait several sec, then jumper R and W/W1 thermostat terminals on furnace con- —...
  • Page 23: Code 32 Low-Pressure Switch Fault

    Fault Code 32 LOW-PRESSURE SWITCH FAULT—This fault can occur under the scenarios shown below. Keep in mind that whenever the furnace control board shuts unit down, gas shuts off immediately, inducer continues running for 15 sec, and if blower is running it remains running at low-heat speed or reduces to low-heat speed for selected off delay.
  • Page 24: Fault Code 33-Limit Switch Fault

    Is inducer blower wheel okay? — If possible, replace inducer blower wheel. Otherwise, replace inducer motor assembly. — — Is there any frost build-up on combustion-air inlet? — The problem is caused by reversed vent and combustion-air pipes or some other moist air entering —...
  • Page 25 Go to page number indicated in Index for CLEANUP AND START-UP INSTRUCTIONS. — — INDEX Consider this fault like a Fault Code 13 and go to page number indicated in Index for Fault Code — — INDEX Do you have 24v between terminals PL1-9 and C? —...
  • Page 26: Fault Code 34-Ignition Proving Fault

    Fault Code 34 IGNITION PROVING FAULT—This fault can indicate 1 of the following: • Flame was not sensed during trial for ignition period. The control will repeat ignition sequence 3 more times before going into Fault 14—IGNITION LOCKOUT. • The flame signal was lost after trial for ignition period. •...
  • Page 27: Fault Code 41-Blower Outside Valid Speed Range

    Make sure perforated disks are in combustion-air vent inlet. — — Check pressure tubing going to gas valve air pressure fitting for kinks. — — Remove gas valve air pressure fitting and check gas valve for blockage. — — Ensure vent and combustion-air pipes are not reversed. —...
  • Page 28 Are ORANGE and VIOLET wires from PL3 and PL13 making good contact? — Replace entire blower motor or blower control module attached to the blower motor. If you replace — — the blower control module go to step 26. Go to page number indicated in Index for CLEANUP AND STARTUP INSTRUCTIONS. If problem persists on an intermittent basis, replace entire blower motor or blower control module attached to —...
  • Page 29: Code 42 Inducer Outside Valid Speed Range

    Fault Code 42 INDUCER OUTSIDE VALID SPEED RANGE—This fault indicates that inducer motor is not operating at calculated RPM or has not started within 10 sec after a call for heat. STEP ACTION GO TO Turn power off, remove blower access panel, and disconnect all thermostat leads from furnace con- —...
  • Page 30: Fault Code 43-Pressure Switch Calibration Fault

    If possible, replace inducer wheel. Otherwise, replace inducer motor assembly. — — Is there any frost build-up on combustion-air inlet? — The problem is caused by reversed vent and combustion-air pipes or some other moist air entering — — combustion-air pipe. You have inadequate combustion-air supply.
  • Page 31 Observe operation of furnace for several minutes or until fault occurs. — — Does fault occur again? — Does a different fault occur? — Go to page number indicated in Index for fault code flashed. — — INDEX Go to page number indicated in Index for CLEANUP AND START-UP INSTRUCTIONS. —...
  • Page 32: Code 44 Blower Calibration Fault

    Fault Code 44 BLOWER CALIBRATION FAULT-This fault indicates that calculated blower motor speed is below 250 or above 1300 RPM. When Fault Code 44 occurs in HEATING, COOLING, or CONTINUOUS FAN mode, unit operates as shown below. Keep in mind that whenever furnace control board shuts unit down in heating mode, gas shuts off immediately, inducer continues running for 15 sec, and blower runs at default (or previous) speed control signal for selected off delay.
  • Page 33: Cleanup And Start-Up Instructions

    CLEANUP AND START-UP INSTRUCTIONS 4. Put setup switch SW-1 in ON position and jumper R, W/W1, and Y/Y2 terminals on furnace control board simultaneously 1. Start furnace using procedure outlined on Lighting Instruc- to clear fault history. tions attached to furnace. Observe operation of furnace through at least 1 complete heating cycle controlled from 5.
  • Page 34: Board Layout And Schematic

    Appendix A Board Layout and Schematic P/N HK42FZ003 P/N HK42FZ012 SURFACE IGNITOR CONNECTOR EAC-ELECTRONIC AIR CLEANER TERMINALS (115-VAC 1 AMP MAX) 115-V CONNECTORS (SEE DETAILS ABOVE) PRESSURE SWITCH CONNECTOR MAIN HARNESS HUM-HUMIDIFIER CONNECTOR TERMINAL (24-VAC 0.5 AMP MAX) MAIN BLOWER CONTROL WIRE 24-V THERMOSTAT CONNECTOR...
  • Page 35 USED) (WHEN LGPS OFF-DELAY BLOWER TEST COMP. HEAT EMER. HEAT 5BLU 4YEL 3VIO EAC2 2ORN EAC1 1RED NOTE IND.
  • Page 36: Appendix B-Isolation Circuits

    Appendix B Isolation Circuits FURNACE CONTROL THERMOSTAT –FIELD-SUPPLIED FIELD-SUPPLIED BOARD 24-VAC SPST RELAY 24-VAC (40VA) TRANSFORMER 120VAC OUTDOOR UNIT THERMOSTAT FURNACE OUTDOOR FIELD-SUPPLIED UNIT CONTROL 24-VAC SPST RELAYS BOARD A95098 A95097 Fig. 6—Isolation of Outdoor Unit with a Separate Fig. 5—Isolation of W/W1 and Y/Y2 24-v Supply Thermostat Circuits Appendix C...
  • Page 37: Appendix D-Quick Motor Test Procedure

    Appendix D Quick Motor Test Procedure In an effort to provide a method of troubleshooting inducer and blower motor by themselves, the following procedure may save you some time in the event any of the following fault codes are the reason for service call (12, 32, 41, 42, or 44). If you get any other fault code, you should use main troubleshooting guide to isolate problem.
  • Page 38 Does blower wheel rub against blower housing? — Does blower wheel turn freely? — Is blower wheel firmly mounted on motor shaft? — Replace blower motor or blower control module attached to the blower motor. If you replace the blower control module go to step 51. Always inspect failed motor for water damage. If present, find —...
  • Page 39 Wait at least 5 minutes after disconnecting line voltage from equipment before opening blower motor to prevent electric shock which can cause personal injury or death. Remove tape from door switch and turn power off at main disconnect. — — Disconnect PL10 from blower assembly.
  • Page 40 Appendix E Variable-Speed Condensing Furnace Duct Static and Blower Operation This variable-speed furnace has an Integrated Control and Motor called an ICM. This ICM is controlled as stated in Sequence of Operation section. This furnace does a good job compensating for an improperly sized duct system, but this ICM is not a fix for all bad ductwork. This troubleshooting guide has shown that the blower does a calibration 20 sec at start of any operation of ICM.
  • Page 41 Air Delivery Curves Air Delivery Curve — 040-14 Air Delivery Curve — 060-14 HIGH HEAT Constant System Constant System Curves Curves HIGH HEAT HEAT HEAT ⁄ ⁄ ⁄ 2 Ton ⁄ 3 Ton ⁄ 2 Ton ⁄ 3 Ton 1000 1100 1200 1300...
  • Page 42: Static Pressure Reading Location Diagrams

    Static Pressure Reading Location Diagrams COMBUSTION AIR PIPE VENT PIPE OUTDOOR UNIT A/C COIL SUPPLY STATIC HUMIDIFIER INCLINE MANOMETER RETURN STATIC GAS-FIRED ELECTRONIC WATER HEATER AIR CLEANER INCLINE MANOMETER AIRFLOW Basement — Upflow Application A95090 Upflow Total Static Pressure Reading Locations ELECTRONIC AIR CLEANER RETURN STATIC...
  • Page 43 RETURN STATIC COMBUSTION–AIR PIPE VENT PIPE INCLINE MANOMETER ELECTRONIC AIR CLEANER SUPPLY STATIC FURNACE CONDENSATE DRAIN AIR CONDITIONING COIL REFRIGERATION INCLINE MANOMETER PIPING AIRFLOW Attic — Horizontal Application A95092 Horizontal Right and Left Airflow Total Static Pressure Reading Locations Example 1 Example 2 Return ESP after filter 0.40 in.
  • Page 44 Duct Static Check Sheet Furnace: Indoor Coil: Model Number Model Number Serial Number Serial Number Position? U/F D/F H/R H/L Outdoor Unit: Model Number Thermostat Serial Number Electronic Air Cleaner What type of media filter is being used? What is static pressure drop across filter? At what CFM? Does fault code go away when you remove filter? What Zone System is applied?
  • Page 45: Quick Reference Information

    Appendix F Quick Reference Information PRESSURE SWITCH MAKE/BREAK POINTS HIGH-PRESSURE SWITCH LOW-PRESSURE SWITCH UNIT SIZE (BTUH) Make Point Break Point Make Point Break Point 40,000 1.81 in. wc max 1.63 in. wc 0.05 0.75 in. wc max 0.60 in. wc 0.05 60,000 80,000...
  • Page 46: Appendix G-Thermostat Staging Algorithm

    Appendix G Thermostat Staging Algorithm • Unit Default: Algorithm is initiated with Low Heat for 16 minutes. If call for heat still exists, unit transfers into High Heat until thermostat is satisfied. • Low Heat run time is calculated based on previous heating cycle. •...
  • Page 48: Service Training

    [ ] Classroom Service Training A94328 Copyright 1999 CARRIER Corp. • 7310 W. Morris St. • Indianapolis, IN 46231 58mvp8sm Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.

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