1. Manuals
  2. Brands
  3. A.O. Smith Manuals
  4. Water Heater
  5. 100 Series
  6. Service handbook

A.O. Smith 100 Series Service Handbook

Commercial boilers/water heaters
Hide thumbs Also See for 100 Series:
Table of Contents

Advertisement

Quick Links

See also: Instruction Manual , Instruction and Installation Manual
Service Handbook
COMMERCIAL BOILERS/WATER HEATERS
FOR MODELS: XB/XWH
1000, 1300, 1700
2000, 2600, 3400
SERIES 100/101
25589 Highway 1
McBee, SC 29101
INSTALLATION CONSIDERATIONS - PRE SERVICE CHECKS
- BOILER/WATER HEATER CONSTRUCTION -
OPERATION & SERVICE - TROUBLESHOOTING
SERVICING SHOULD ONLY BE PERFORMED BY A QUALIFIED SERVICE AGENT
PRINTED IN THE U.S.A. 0513
320822-003

Advertisement

Table of Contents
loading

Related Manuals for A.O. Smith 100 Series

Summary of Contents for A.O. Smith 100 Series

  • Page 1 Service Handbook COMMERCIAL BOILERS/WATER HEATERS FOR MODELS: XB/XWH 1000, 1300, 1700 2000, 2600, 3400 SERIES 100/101 25589 Highway 1 McBee, SC 29101 INSTALLATION CONSIDERATIONS - PRE SERVICE CHECKS - BOILER/WATER HEATER CONSTRUCTION - OPERATION & SERVICE - TROUBLESHOOTING SERVICING SHOULD ONLY BE PERFORMED BY A QUALIFIED SERVICE AGENT PRINTED IN THE U.S.A.
  • Page 2 Servicing should only be performed by a Qualified Service Agent...

  • Page 3: Table Of Contents

    TABLE OF CONTENTS TABLE OF CONTENTS ................3 Burner Control Operation ..............40 INTRODUCTION ..................4 General Operational Sequence ............41 Qualifications ..................4 Lead Lag ..................42 Service Warning ................4 Local operator interface: display system ......... 44 Service Reminder ................4 Installation Instructions (S7999D OI Display) ........

  • Page 4: Introduction

    INTRODUCTION This Service Manual covers the models and series numbers listed on the front cover only. The instructions and illustrations contained in this manual will provide you with troubleshooting procedures to verify proper operation and diagnose and repair common service problems.

  • Page 5: Installation Considerations

    INSTALLATION CONSIDERATIONS This section of the Service Manual covers some of the critical installation requirements that, when overlooked, often result in operational problems, down time and needless parts replacement. Costs to correct installation errors are not covered under the limited warranty. Ensure all installation requirements and instructions contained in the Instruction Manual that came with the boiler/ water heater have been followed prior to performing any service procedures.

  • Page 6: Venting

    VENTING This section of the Service Manual is not a complete venting installation instruction. Refer to the Instruction Manual that came with the boiler/water heater; ensure the venting has been installed per all Instruction Manual requirements. Failing to install the factory provided vent and/or intake air terminations, exceeding the maximum equivalent vent and/or intake air piping lengths, adding too many elbows to the intake air and/or vent pipes, installing the wrong vent intake air pipe size, will cause operational problems, improper combustion, rough starting/operation and Control System lock out costs to correct installation errors are not covered under...

  • Page 7: Boiler/Water Heater Controls

    BOILER/WATER HEATER CONTROLS The controls that are improperly installed or configured can cause serious operational and service related problems such as short cycling. This section provides information for how various controls can work together or independently to provide proper boiler/water heater and system control.

  • Page 8: Installation Checklist

    INSTALLATION CHECKLIST The list below represents some of the most critical installation requirements that, when overlooked, often result in operational problems, down time and needless parts replacement. Before performing any troubleshooting procedures use the list below to check for installation errors. Costs to correct installation errors are not covered under the limited warranty. Ensure all installation requirements and instructions contained in the Instruction Manual that came with the boiler/water heater have been observed and followed.

  • Page 9: Features And Components

    FEATURES AND COMPONENTS FRONT VIEW BACK VIEW VENT (EXHAUST) HIGH VOLTAGE CONNECTION BOX AIR FILTER BOX SENSOR/COMMUNICATION BOX TOUCH SCREEN DISPLAY PRESSURE RELIEF MAIN POWER VALVE SUPPLY SWITCH WATER OUTLET ALL BRONZE CIRCULATION PUMP. FACTORY INSTALLED AT INLET WATER CONNECTION XB MODELS - OPTIONAL XWH MODELS - STANDARD CONDENSATE TRAP...
  • Page 10 BACK VIEW FRONT VIEW SENSOR/COMMUNICATION BOX AIR FILTER BOX HIGH VOLTAGE CONNECTION BOX WATER OUTLET TOUCH SCREEN DISPLAY MAIN POWER SUPPLY SWITCH VENT (EXHAUST) ALL BRONZE CIRCULATION PUMP. FACTORY INSTALLED AT INLET WATER CONNECTION XB MODELS - OPTIONAL XWH MODELS - STANDARD WATER INLET SIDE VIEW CONDENSATE TRAP...

  • Page 11: Operation And Service

    OPERATION AND SERVICE MODULATING FIRE OPERATION XB boilers & XWH water heaters are modulating systems. The control system modulates the firing rate of the burner to match system load by controlling the speed of the combustion blower. They do not have a gas orifice. The combustion blower "pulls" fuel gas from the outlet of the 24 VAC gas valve (when energized) into a venturi that is connected to the inlet of the Combustion Blower.

  • Page 12: Heat Exchanger Assembly

    HEAT EXCHANGER ASSEMBLY The heat exchanger transfers heat from the hot flue gases to the heating system’s water. Combustion products including flue gas condensate, which are formed in the heat exchanger are evacuated. The heat exchanger includes the following interfaces: •...
  • Page 13 Water Connection Heat Exchangers are equipped with 2 water male connections with NPT threading, according to the ANSI/ASME B1.20.1 standard, which are sized according to the capacity of the heat exchanger. Flue Gas Outlet Connection The heat exchanger is equipped with an evacuation for the combustion products at the back side. Flue gas outlets are sized according to the capacity of the heat exchanger.

  • Page 14: Venturi And Gas Train Assembly

    VENTURI AND GAS TRAIN ASSEMBLY The gas train includes a venturi connected to the inlet of the combustion blower. The outlet of the 24 VAC gas valve is also connected to the venturi by a manifold gas line. There is a shutoff valve installed in the manifold gas line for start up and service procedures. The venturi contains a convergent/divergent nozzle (cone shaped restrictor) that constricts the air passage to the blower.

  • Page 15: Burner Assembly

    BURNER ASSEMBLY The burner is a stainless steel radial fire burner with a woven steel fiber surface. It is installed in the center of the horizontal heat exchanger. The burner is mounted inside the recess of the heat exchanger. The spark igniter on the boiler/water heater is a 120VAC igniter. The igniter receives power from the J5 socket on the Control Board. The 110V from the board is then passed to an ignition transformer.
  • Page 16 FIGURE 8. BURNER ASSEMBLY (1300/2600) FIGURE 9. BURNER ASSEMBLY (1700/3400) Servicing should only be performed by a Qualified Service Agent...

  • Page 17: Flame Sensor

    FLAME SENSOR Ignition of the burner is controlled electronically. The principle of operation for electronic ignition relies on flame sensing voltage to prove the fuel gas flowing to the burner has been ignited and is burning safely. Flame sensing requires correct power supply polarity and an adequate earth ground to the boiler/water heater's burner. See Figure 7 on Page 15, Figure 8 and Figure 9 on Page 16 for the Burner Assembly.

  • Page 18: Spark Igniter

    SPARK IGNITER The Spark Igniter is made of a ceramic composite material, see Figure 11 below. The Control System powers the Spark Igniter (120 VAC) from the pin 6, J5 connector on the Control Board to the External Spark Transformer. Spark Igniters are service parts, over time Spark Igniters will wear out and must be replaced as they will no longer generate enough spark to cause ignition.

  • Page 19: Gas Valve

    GAS VALVE The 24 Volt Gas Valve on the XB Boilers/XWH water heaters is AC voltage valve. The Control Board sends 24 VAC to the gas valve. See Figure 6 on Page 14. Gas Valve Voltage Test • Check for 24 VAC supplied to the 24 Volt Gas Valve at pin 2 of the J5 Connector on the Control Board. Using an "AC" volt meter connect one lead to pin 2 of the J5 Connector and the other lead to ground.

  • Page 20: Temperature Sensors

    TEMPERATURE SENSORS Temperature sensors are 3/4 inch male threaded immersion probes. Temperature probes have embedded temperature sensors (thermistors). The boiler/water heater’s control system monitors these sensors to determine water temperature at various points in the system. Thermistors are thermally sensitive resistors; as the surrounding temperature rises the resistance of the thermistor (measured in ohms) will decrease and as the surrounding temperature falls the resistance of the thermistor increases.

  • Page 21: Air Filter Assembly

    AIR FILTER ASSEMBLY FIGURE 13. AIR FILTER ASSEMBLY Air Filter Assembly is mounted on the top panel of the XB boilers/ XWH water heaters. See Figure 2 on Page 9 and Figure 3 on Page 10. The assembly includes a filter which slides inside the filter housing and filter brackets. The filter is made of of wire mesh screen and is meant to block dust particles and other debris from entering through the air intake into the boiler/water heater.

  • Page 22: Control Panel Assembly

    CONTROL PANEL ASSEMBLY Figure 14, Figure 15 on Page 23 and Figure 16 on Page 24 shows the Control Panels Assemblies for the XB boilers/XWH water heaters. The main components include Control Boards (Master & Local), Display Power Supply, 24 VAC Terminal Block, Step Down Transformer, Pump Relay, Fuse Block, Input Power 120 VAC Terminal Block, Low Water Cutoff Device and Interlock/Load Control Input (ILK/LCI) Relays.
  • Page 23 FIGURE 15. UPPER CONTROL PANEL ASSEMBLY (2000/2600/3400) Servicing should only be performed by a Qualified Service Agent...
  • Page 24 FIGURE 16. LOWER CONTROL PANEL ASSEMBLY (2000/2600/3400) Servicing should only be performed by a Qualified Service Agent...

  • Page 25: Control Board Assembly

    CONTROL BOARD ASSEMBLY The Control Board assembly provides heat control, flame supervision, circulation pump control, fan control, boiler/water heater control sequencing, and electric ignition function. It will also provide boiler/water heater status and error reporting. The Control Board may consist of Control Device, Touchscreen Display (required for setup and ModBus communication, but not required for the system to operate once the Control Device is programmed), Local Operator Interface (which can set up and monitor the Control Device), Local Keyboard Display Module, Flame Rod, Temperature Sensor (NTC Type 10KΩ...
  • Page 26 FIGURE 17. CONTROL BOARD ASSEMBLY Servicing should only be performed by a Qualified Service Agent...
  • Page 27 TABLE 3. CONTROL BOARD CONTACTS/CONNECTIONS CONNECTORS PINS TERMINOLOGY DESCRIPTION AND RATING Not Used FLAME SENSE1/2: SENSE Flame Rod Input. FLAME SENSE1/2: GND Flame Rod Common. Not Used Not Used Not Used TACH Tachometer Input (Tach). 25VDC Electronic Blower Motor Power (25 VDC). Digital modulation (PWM) Output Digital modulation signal out.
  • Page 28 CONNECTORS PINS TERMINOLOGY DESCRIPTION AND RATING SIPHON Condensation Switch Input. Flapper Switch Input. Not Used SYS_ENABLE Annunciator for System Enable Switch. Annunciator for Low Gas Pressure Switch. Annunciator for High Gas Pressure Switch. Not Used SOLA1_PWR 24VAC Power Input form Terminal Block. SOLA1_S_RTN 24VAC Return Input from Terminal Block.

  • Page 29: Display System (Touch Screen Display)

    DISPLAY SYSTEM (TOUCH SCREEN DISPLAY) The Display System is a microprocessor-based color touchscreen Operator Interface (OI) display that provide an operator interface for monitoring and configuring parameters such as burner control sequence, flame signal, diagnostics, historical files, and faults in the Control System.
  • Page 30 FIGURE 19. DISPLAY CONNECTOR TERMINALS SCHEMATIC DIAGRAM FIGURE 20. DISPLAY CONNECTOR TERMINALS LEAD LAG DIAGRAM Servicing should only be performed by a Qualified Service Agent...

  • Page 31: Start Up And Operations

    START UP AND OPERATIONS PRIOR TO START UP In addition to normal supplies and hand tools necessary for installing and servicing the boilers/water heaters, other tools and test equipment should be on hand. See Tools Required on Page 4 for detailed tool requirements. Only an A.

  • Page 32: Manifold Pressure Connections

    MANIFOLD PRESSURE CONNECTIONS Check the manifold pressure (refer to Table 2 on Page 19) by removing the pipe plug (located on the back of the boiler/water heater near the main gas shutoff valve) and inserting a suitable 1/8” NPT hose barb for connection to the manometer/pressure gauge. Upon completion of measurements and adjustments, remove the hose barb and replace the pipe plug.

  • Page 33: Check/Control Water Hardness

    CHECK/CONTROL WATER HARDNESS XWH water heaters are approved for use in Domestic Water Heating Systems with a water supply hardness of 0 grains per gallon to a maximim of 12 grains per gallon and a Total Dissolved Solids (TDS) not exceeding 350 PPM. Heating water having higher grains/TDS specified here requires larger circulating pump.

  • Page 34: Lighting And Operating Instructions

    LIGHTING AND OPERATING INSTRUCTIONS Servicing should only be performed by a Qualified Service Agent...

  • Page 35: Adjustment

    ADJUSTMENT There must be sufficient load to operate the boiler/water heater at high fire to perform the following adjustments. Start the boiler/water heater and observe proper operating parameters for the system. Required Tools: • TORX T40 or 5 mm hex wrench ®...
  • Page 36 FIGURE 24. OPERATION SCREEN FIGURE 25. FIRING RATE PAGE HIGH FIRING RATE SETTING Set the boiler/water heater to the high firing rate by setting the High Firing Rate RPM as described below. Check combustion readings using a combustion analyzer. If combustion readings are not in accordance with the chart below adjust the gas valve as follows: remove the flat, round, blue plastic cap from the cover.
  • Page 37 LOW FIRING RATE SETTING Set the boiler/water heater to the low firing rate by setting the Low Firing Rate RPM as described below. Check combustion readings using a combustion analyzer. If combustion readings are not in accordance with the chart shown below adjust as follows: remove the cap on the gas regulator using a slotted screwdriver.

  • Page 38: Control System Operations

    CONTROL SYSTEM OPERATIONS BURNER CONTROL SYSTEM FIGURE 26. R7910A1138 CONTROL SYSTEM The R7910A1138 is a burner control system that provide heat control, flame supervision, circulation pump control, fan control, boiler/ water heater control sequencing, and electric ignition function. It will also provide boiler/water heater status and error reporting. Multiple boiler/water heaters can be joined together to heat a system instead of a single, larger burner or boiler/water heater.
  • Page 39 COMMUNICATIONS AND DISPLAYS Two modes of communications are available to the R7910. The R7910 has two RS485 communication ports for ModBus that allows for interfacing to one or all R7910s of a system and presents them individually to the user. The S7999D System Operator interface is a color touchscreen display used for configuration and monitoring of the R7910A.

  • Page 40: Burner Control Operation

    BURNER CONTROL OPERATION Safety Shutdown of Burner Control Functions Safety Shutdown (Lockout) occurs if any of the following occur during the indicated period: INITIATE PERIOD: a. A/C line power errors occurred. b. Four minute INITIATE period has been exceeded. 2. STANDBY PERIOD: a.

  • Page 41: General Operational Sequence

    Safety Shutdown: If the lockout interlocks open or a sensor designated as a safety limit are read as defective, Control System will lockout and the blower motor will be de-energized. If these open during the firing period, all fuel valves will be de-energized, the system will complete postpurge, and will lockout indicated by an alarm.

  • Page 42: Lead Lag

    Domestic Hot Water Start-up sequence DHW-request (system in standby): Heat request detected (Tank Sensor below Setpoint). The pump is switched on. After a system Safe Start Check, the Blower (fan) is switched on after a dynamic ILK switch test (if enabled). After the ILK switch is closed and the purge rate proving fan RPM is achieved (or High Fire Switch is closed) - prepurge time is started.
  • Page 43 The LL master may be aware of slave Burner Control’s minimum firing rate and use this information for some of its algorithms, but when apportioning rate it may also assign rates that are less than this. In fact, the add-stage and drop-stage algorithms may assume this and be defined in terms of theoretical rates that are possibly lower than the actual minimum rate of the Burner Control.

  • Page 44: Local Operator Interface: Display System

    LOCAL OPERATOR INTERFACE: DISPLAY SYSTEM FIGURE 27. S7999D DISPLAY SYSTEM The S7999D is a microprocessor-based touchscreen Operator Interface (OI) display that provide an operator interface for monitoring and configuring parameters in the Burner Control system. The S7999D is used to monitor an individual burner on the XB Boilers/XWH Water Heaters applications in a lead/lag arrangement. It consists of 2 RS485 ports (COM 1 &...

  • Page 45: Installation Instructions (S7999D Oi Display)

    Approvals: FCC Part 15, Class A Digital Device Underwriter’s Laboratories, Inc. (UL) (cUL) Component Recognized (for non-continuous operation): File Number MH17367 (MJAT2, MJAT8). INSTALLATION INSTRUCTIONS (S7999D OI DISPLAY) Mounting the S7999D OI Display and Power Supply The OI Display can be mounted on the door panel of an electrical enclosure. Select the location on the door panel to mount the display;...
  • Page 46 STARTING UP THE S7999D OI DISPLAY Power-up Validation The Home page will appear when the device is properly powered. Select the Setup button to adjust the contrast and sound as desired. If the screen is dim, check the pin 7 and 8 wiring connections. A “camera”...
  • Page 47 FIGURE 31. S7999D DISPLAY PAGE FLOW Servicing should only be performed by a Qualified Service Agent...

  • Page 48: Page Navigation

    On System applications, each Burner Control is represented on the Home page by an icon and name. Pressing the icon allows the user to zoom in on that burner and see its specific details. These details are provided on a new page, which can include additional buttons that display additional detail and operation information, which itself leads to other pages.
  • Page 49 FIGURE 32. SUMMARY STATUS PAGE (HYDRONIC CONTROL) CONFIGURE BUTTON The configuration page allows the user to view and set parameters that define how the connected Burner Control System R7910A functions. The configuration page allows the user to view and set parameters that define how the connected R7910A functions in the hydronic heating system.
  • Page 50 CONFIGURATION PASSWORD Some parameters require a valid configuration password be entered by the user before the parameter can be changed. The password need only be entered once while the user remains on the configuration pages and stays active. The display times out after 10 minutes of inactivity.
  • Page 51 LOGIN Pressing the Login button allows entering the password from a keyboard as shown in Figure 36. After the password is entered, the OK button is selected. The Cancel button aborts the password login. FIGURE 36. DEVICE LOGIN SCREEN WARNING: Explosion Hazard. Improper configuration can cause fuel buildup and explosion. Improper user operation may result in property loss, physical injury or death.
  • Page 52 FIGURE 38. SAFETY VERIFICATION FIGURE 39. EDIT SAFETY DATA NOTE: When the installer proceeds with the safety parameter configuration, the control unlocks the safety parameters in this group and marks them unusable. Failure to complete the entire safety configuration procedure leaves the control in an un-runnable state (lockout 2).
  • Page 53 FAULT/ALARM HANDLING Each Burner Control reports to the OI display when a safety lockout or an Alert occurs. Safety lockouts are indicated on each configuration page as an alarm bell symbol. At the status page (for S7999D), the History button turns red.
  • Page 54 FIGURE 42. EXAMPLE OF HISTORY BUTTON Two types of historical data can be displayed on the history page: lockout history and alert log. The entire 15 fault code history is displayed in a scrollable list with the most recent fault displayed first followed by the next most recent fault.
  • Page 55 FIGURE 45. CONTROL EXPANDED LOCKOUT DETAIL FIGURE 46. CONTROL EXPANDED ALERT DETAIL OPERATION BUTTON The operation button displays the Burner Control running operation, including setpoint and firing rate values. From this page the user can change setpoints, manually control the boiler/water heater’s firing rate, manually turn pumps on, view annunciation information, and switch between hydronic heating loops (Central Heat and Domestic Hot Water), as shown in Figure 47.
  • Page 56 DIAGNOSTICS BUTTON The Diagnostics button displays analog and digital I/O status of the Burner Control and is meant only for diagnostics and troubleshooting purposes. A snapshot of the diagnostic status is displayed and updated once per second as it changes in the control. The digital I/O data is displayed as LEDs that are either on (green) or off (red) (see Figure 50).
  • Page 57 SYSTEM SYNCHRONIZATION (S7999D OI CONFIGURATION DISPLAY ONLY) The Burner Control can be configured from the OI Display. The control configuration is grouped into the functional groups as The user can manually synchronize configuration data from the shown in Table 11. connected controls at any time.

  • Page 58: Troubleshooting

    TROUBLESHOOTING The Control System performs exhaustive self diagnostics and displays detected fault conditions in plain English errors/fault messages on the Display System when there is a problem. When the Control System declares a fault condition it will “lock out” and disable boiler/water heater operation.
  • Page 59 RESTORE GAS FLOW SETTINGS TO DEFAULT Each XB boiler/XWH water heater is fired and the optimal combustion set before leaving the factory. The High and Low Fire gas flow adjustment screws on the 24 VAC Gas Valve have been set to maximize the boiler/water heater performance. When performing the on site Start-up, gas flow can be improperly adjusted to the point the boiler/water heater will not light.

  • Page 60: Troubleshooting Codes

    TROUBLESHOOTING CODES To support the recommended Troubleshooting, the R7910 has an Alert File. Review the Alert history for possible trends that may have been occurring prior to the actual Lockout. Note Column: H= Hold message; L=Lockout message; H or L= either Hold or Lockout depending on Parameter Configuration. TABLE 12.
  • Page 61 CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF NOTE LOCKOUT CODES Internal fault: Flame bias shorted to adjacent pin Internal Fault. Reset Module. Internal fault: SLO electronics unknown error If fault repeats, replace module. 32 - 46 Internal fault: Safety Key 0 through 14 System Errors Flame Rod to ground leakage Static flame (not flickering)
  • Page 62 CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF NOTE LOCKOUT CODES ILK OFF Check wiring and correct any possible shorts. H or L Check Interlock (ILK) switches to assure proper ILK ON H or L function. Verify voltage through the interlock string to the interlock input with a voltmeter.
  • Page 63 CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF NOTE LOCKOUT CODES Header sensor fault Check wiring and correct any possible errors. Replace the header sensor. If previous steps are correct and fault persists, replace the module. Stack sensor fault Check wiring and correct any possible errors. Replace the stack sensor.
  • Page 64 CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF NOTE LOCKOUT CODES Lightoff rate proving failed Check wiring and correct any potential wiring errors. Purge rate proving failed Check VFDs ability to change speeds. Change the VFD. If the fault persists, replace the module. High fire switch OFF Check wiring and correct any potential wiring errors.
  • Page 65 CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF NOTE LOCKOUT CODES Flame detected OEM Specific. H or L Holds if flame detected during Safe Start check up to Flame Establishing period. Flame not detected OEM Specific. Sequence returns to standby and restarts sequence at the beginning of Purge after the HF switch opens.
  • Page 66 CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF NOTE LOCKOUT CODES Block intake ON OEM Specific. Check wiring and correct any errors. Block intake OFF Inspect the Block Intake Switch to make sure it is working correctly. Reset and sequence the module. During Standby and Purge, measure the voltage across the switch.
  • Page 67 CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF NOTE LOCKOUT CODES Invalid Preignition time setting Return to Configuration mode and recheck selected parameters, reverify and reset module. Invalid Prepurge rate setting If fault repeats, verify electrical grounding. Invalid Prepurge time setting If fault repeats, replace module. Invalid Purge rate proving setting Invalid Run flame failure response setting Invalid Run stabilization time setting...
  • Page 68 TABLE 13. ALERTS CODE DESCRIPTION CODE DESCRIPTION EE Management Faults Program Module application parameter revision differs from application processor None (No alert) Program Module safety parameter revision differs Alert PCB was restored from factory defaults from safety processor Safety configuration parameters were restored PCB incompatible with product contained in from factory defaults Program Module...
  • Page 69 CODE DESCRIPTION CODE DESCRIPTION Fan Parameter Errors MIX modulation range (max minus min) was too small (< 4% or 40 RPM) Periodic Forced Recycle Modulation Operation Faults Absolute max fan speed was out of range Fan was limited to its minimum duty cycle Absolute min fan speed was out of range Manual rate was >...
  • Page 70 CODE DESCRIPTION CODE DESCRIPTION Minimum water temperature parameter was Lead Lag base load common setting was invalid greater than time of day setpoint Lead Lag DHW demand switch setting was Minimum pressure parameter was greater than Lead Lag Mix demand switch setting was invalid setpoint Lead Lag modulation sensor setting was invalid Minimum pressure parameter was greater than...
  • Page 71 CODE DESCRIPTION CODE DESCRIPTION Lead Lag CH setpoint was invalid Abnormal Recycle: Demand off during Pilot Flame Establishing Period Lead Lag CH time of day setpoint was invalid Abnormal Recycle: LCI off during Drive to Purge LL outdoor temperature was invalid Rate Lead Lag ODR time of day setpoint was invalid Abnormal Recycle: LCI off during Measured Purge...
  • Page 72 CODE DESCRIPTION CODE DESCRIPTION Abnormal Recycle: ILK off during Measured Purge Abnormal Recycle: Hardware SLO electronics Time Abnormal Recycle: Hardware processor clock Abnormal Recycle: ILK off during Drive to Lightoff Abnormal Recycle: Hardware AC phase Rate Abnormal Recycle: Hardware A2D mismatch Abnormal Recycle: ILK off during Pre-Ignition test Abnormal Recycle: Hardware VSNSR A2D Abnormal Recycle: ILK off during Pre-Ignition time...
  • Page 73 CODE DESCRIPTION CODE DESCRIPTION Abnormal Recycle: Fan Speed Range High Internal error: Safety key bit 4 was incorrect 383-450 RESERVED Internal error: Safety key bit 5 was incorrect Circulator Errors Internal error: Safety key bit 6 was incorrect Circulator control was invalid Internal error: Safety key bit 7 was incorrect Circulator P-gain was invalid Internal error: Safety key bit 8 was incorrect...
  • Page 74 CODE DESCRIPTION CODE DESCRIPTION Mix circulator sensor was invalid Heat exchanger high limit response was invalid Mix flow control was invalid Heat exchanger high limit was exceeded Mix temperature was invalid Heat exchanger high limit wasn't allowed due to stack limit setting Mix sensor was invalid Heat exchanger high limit wasn't allowed due to Mix PID setpoint was invalid...

  • Page 75: Piping Diagrams

    PIPING DIAGRAMS Servicing should only be performed by a Qualified Service Agent...
  • Page 76 Servicing should only be performed by a Qualified Service Agent...
  • Page 77 NOTES Servicing should only be performed by a Qualified Service Agent...
  • Page 78 NOTES Servicing should only be performed by a Qualified Service Agent...
  • Page 79 NOTES Servicing should only be performed by a Qualified Service Agent...
  • Page 80 25589 Highway 1, McBee, SC 29101 Technical Support: 800-527-1953 • Parts: 800-433-2545 • Fax: 800-644-9306 www.hotwater.com Copyright © 2013 A. O. Smith Water Heater Company, All rights reserved.

This manual is also suitable for:

101 seriesXb 1000Xb 1300Xwh 1000Xwh 1300Xwh 1700 ... Show all

Table of Contents