Service Handbook COMMERCIAL BOILERS/WATER HEATERS 25589 Highway 1 McBee, SC 29101 FOR MODELS: XB/XWH 1000, 1300, 1700 2000, 2600, 3400 SERIES 100/101 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.
Servicing should only be performed by a Qualified Service Agent
TABLE OF CONTENTS TABLE OF CONTENTS �������������������������������������������������������������������������� 3 Burner Control Operation ���������������������������������������������������������������� 40 INTRODUCTION ������������������������������������������������������������������������������������ 4 General Operational Sequence ������������������������������������������������������� 41 Qualifications ������������������������������������������������������������������������������������� 4 Lead Lag �
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. QUALIFICATIONS QUALIFIED INSTALLER OR SERVICE AGENCY Installation and service of this boiler/water heater requires ability equivalent to that of a Qualified Agency (as defined by ANSI below) in the field involved.
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.
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.
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.
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.
FEATURES AND COMPONENTS FRONT VIEW BACK VIEW VENT (EXHAUST) HIGH VOLTAGE CONNECTION BOX AIR FILTER BOX SENSOR/COMMUNICATION BOX TOUCH SCREEN DISPLAY PRESSURE RELIEF VALVE MAIN POWER WATER OUTLET SWITCH SUPPLY ALL BRONZE CIRCULATION PUMP. FACTORY INSTALLED AT INLET WATER CONNECTION XB MODELS - OPTIONAL XWH MODELS - STANDARD CONDENSATE TRAP SIDE VIEW MAIN GAS SHUT OFF VALVE VENT (EXHAUST) CONNECTION 7 INCH AL29-4C STAINLESS STEEL WATER OUTLET WATER INLET Figure 2.
BACK VIEW FRONT VIEW SENSOR/COMMUNICATION BOX AIR FILTER BOX HIGH VOLTAGE CONNECTION BOX TOUCH SCREEN DISPLAY WATER OUTLET 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 PRESSURE RELIEF VALVE VENT (EXHAUST) CONNECTION 7 INCH AL29-4C STAINLESS STEEL WATER OUTLET WATER INLET Figure 3.
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.
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: • 2x Burner doors • Flue gas outlet connection • Water inlet and outlet connection • Condensate connection • Bushes for sensor Heat from the hot flue gases is transferred to the heating water through a spiral tube made from stainless steel.
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. A. O.
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. As air enters the constriction point its velocity increases.
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. From the ignition transformer the spark ignitier is energized.
Figure 8. BURNER ASSEMBLY (1300/2600) Figure 9.
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. Figure 10.
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.
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. 24 VAC should be present.
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.
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.
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. Figure 14.
Figure 15.
Figure 16.
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.
Figure 17.
CONNECTORS J1 J2 PINS 1 Not Used 2 FLAME SENSE1/2: SENSE Flame Rod Input. 3 FLAME SENSE1/2: GND Flame Rod Common. 4 Not Used 5 Not Used 6 Not Used 1 TACH Tachometer Input (Tach). 2 25VDC Electronic Blower Motor Power (25 VDC). 3 PWM Digital modulation (PWM) Output Digital modulation signal out. 4 GND Ground pin for Fan interface and power. A Modbus MB1 RS-485 +. Connects to Display. B Modbus MB1 RS-485 -. Connects to Display. C Modbus MB1 Ground (G). Connects to Display.
CONNECTORS J7 J8 J9 J10 PINS TERMINOLOGY DESCRIPTION AND RATING 1 SIPHON Condensation Switch Input. 2 F1 Flapper Switch Input. 3 Not Used 4 SYS_ENABLE Annunciator for System Enable Switch. 5 LGP Annunciator for Low Gas Pressure Switch. 6 HGP Annunciator for High Gas Pressure Switch. 7 Not Used 1 SOLA1_PWR 24VAC Power Input form Terminal Block. 2 SOLA1_S_RTN 24VAC Return Input from Terminal Block.
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. It can be used to monitor an individual boiler/water heater but is primarily used for multiple boiler/water heater applications in a lead/lag arrangement.
Figure 19. DISPLAY CONNECTOR TERMINALS SCHEMATIC DIAGRAM Figure 20.
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. O. Smith Certified Start-up agent must perform the initial firing of the boiler/water heater. At this time the user should not hesitate to ask the start-up agent any questions regarding the operation and maintenance of the unit.
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. Check for gas leaks and insure all connections are gas tight. The draft pressures can range in between 0.05" - 1.5" W.C.
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. Consult manufacturer when heating water exceeding these specs. Refer to Table 6 for recommend flow rate to maintain scale free operation with up to a medium water hardness.
LIGHTING AND OPERATING INSTRUCTIONS 34 Servicing should only be performed by a Qualified Service Agent
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 • 3 mm or 7/64 inch hex wrench • Combustion analyzer These boilers/water heaters are equipped with a Honeywell combined gas/air control and gas safety shut off control valves.
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. For more information, refer to the Instruction Manual.
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. For more information, refer to the Instruction Manual. This will expose the offset adjustment screw.
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.
COMMUNICATIONS AND DISPLAYS Two modes of communications are available to the R7910. 1. 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. Though configuration can be done through the display, it is not recommended as all the parameters are pre-configured by the manufacturer.
BURNER CONTROL OPERATION Safety Shutdown of Burner Control Functions Safety Shutdown (Lockout) occurs if any of the following occur during the indicated period: 1. INITIATE PERIOD: a. A/C line power errors occurred. b. Four minute INITIATE period has been exceeded. 2. STANDBY PERIOD: a. Flame signal is present after 240 seconds. b. Main Valve Terminal is energized. c. Internal system fault occurred. 3. PREPURGE PERIOD: a. Flame signal is detected for 10 seconds accumulated time during PREPURGE. b.
Safety Shutdown: 1. 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. 2.
Domestic Hot Water Start-up sequence DHW-request (system in standby): 1. Heat request detected (Tank Sensor below Setpoint). 2. The pump is switched on. 3. After a system Safe Start Check, the Blower (fan) is switched on after a dynamic ILK switch test (if enabled). 4. 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. 5.
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.
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 & COM 2) and USB port.
6. 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. 1.
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” icon on the left top corner is for screen snapshot use. Up to 16 snapshots can be stored in the display and can be copied to a USB memory stick. Note: An Advanced Startup screen displays for five seconds after power-up before the Home page displays.
Figure 31.
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. The pages are traversed in a tree structure method, as shown in Figure 31 on Page 47.
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. All parameters are factory configured and only a qualified service technician must perform the configuration settings). Figure 33.
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. User will have to login again if another secure parameter needs to be changed by pressing the Padlock button. Three levels of access to Burner Control parameters are permitted.
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.
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). All safety configuration parameters in the group should have the same access level.
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. If the S7999D is displaying the system status icons, the control in alarm will turn red. The lockout history can be displayed by pressing on the History button.
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. Summary information is displayed for each fault entry, including the burner cycle count, fault code, and fault number with description.
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.
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).
SYSTEM SYNCHRONIZATION (S7999D OI DISPLAY ONLY) The user can manually synchronize configuration data from the connected controls at any time. A new control is visible when configuration and status data is gathered from it. This collection procedure takes a few minutes. The control is marked as “Unknown” when no configuration information exists. Normally, control configuration data collection only needs to be performed when the control is initially installed.
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. POOR COMBUSTION - IGNITION FAILURE - ROUGH START/OPERATION • Ensure the correct type of fuel gas, natural gas or propane, is supplied to the boiler/water heater.
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.
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. TROUBLESHOOTING CODES CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF LOCKOUT CODES NOTE Safety Data Faults 1 Unconfigured safety data 2 Waiting for safety data verification 1.
CODE DESCRIPTION 30 Internal fault: Flame bias shorted to adjacent pin 31 Internal fault: SLO electronics unknown error 32 - 46 Internal fault: Safety Key 0 through 14 RECOMMENDED TROUBLESHOOTING OF LOCKOUT CODES Internal Fault. 1. Reset Module. 2. If fault repeats, replace module. NOTE H H L System Errors 47 Flame Rod to ground leakage H 48 Static flame (not flickering) H 49 24VAC voltage low/high 1. 2.
CODE DESCRIPTION 67 ILK OFF 68 ILK ON RECOMMENDED TROUBLESHOOTING OF LOCKOUT CODES 1. 2. 3. 4. NOTE Check wiring and correct any possible shorts. Check Interlock (ILK) switches to assure proper function. Verify voltage through the interlock string to the interlock input with a voltmeter. If steps 1-3 are correct and the fault persists, replace the module. H or L H or L 69 Pilot test hold 1. 2. 3. Verify Run/Test is changed to Run. Reset Module. If fault repeats, replace module.
CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF LOCKOUT CODES NOTE 94 Header sensor fault 1. 2. 3. Check wiring and correct any possible errors. Replace the header sensor. If previous steps are correct and fault persists, replace the module. H 95 Stack sensor fault 1. 2. 3. Check wiring and correct any possible errors. Replace the stack sensor. If previous steps are correct and fault persists, replace the module. H 96 Outdoor sensor fault 1. 2. 3.
CODE DESCRIPTION 122 Lightoff rate proving failed 123 Purge rate proving failed 124 High fire switch OFF 125 High fire switch stuck ON RECOMMENDED TROUBLESHOOTING OF LOCKOUT CODES 1. 2. 3. 4. 1. 2. 3. 4. 126 Low fire switch OFF 1. 127 Low fire switch stuck ON 2. 3. 4. 128 Fan speed failed during prepurge 129 Fan speed failed during preignition 130 Fan speed failed during ignition 131 Fan movement detected during standby 132 Fan speed failed during run 133-135 RESERVED 1. 2. 3.
CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF LOCKOUT CODES NOTE 149 Flame detected OEM Specific. 1. Holds if flame detected during Safe Start check up to Flame Establishing period. H or L 150 Flame not detected OEM Specific. 1. Sequence returns to standby and restarts sequence at the beginning of Purge after the HF switch opens. If flame detected during Safe Start check up to Flame Establishing period. H 151 High fire switch ON OEM Specific. 1.
CODE DESCRIPTION 164 Block intake ON 165 Block intake OFF 166-171 RESERVED RECOMMENDED TROUBLESHOOTING OF LOCKOUT CODES NOTE OEM Specific. 1. Check wiring and correct any errors. 2. Inspect the Block Intake Switch to make sure it is working correctly. 3. Reset and sequence the module. 4. During Standby and Purge, measure the voltage across the switch. Supply voltage should be present. If not, the Block Intake Switch is defective and needs replacing. 5.
CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF LOCKOUT CODES 1.
Table 13.
CODE DESCRIPTION Fan Parameter Errors 74 Periodic Forced Recycle 75 Absolute max fan speed was out of range 76 Absolute min fan speed was out of range 77 Fan gain down was invalid 78 Fan gain up was invalid 79 Fan minimum duty cycle was invalid 80 Fan pulses per revolution was invalid 81 Fan PWM frequency was invalid 82-83 RESERVED Modulation Parameter Errors 84 Lead Lag CH 4-20mA water temperature setting 85 No Lead Lag add stage error threshold was configured 86 No Lead Lag add st
CODE DESCRIPTION CODE DESCRIPTION 152 Minimum water temperature parameter was greater than time of day setpoint 191 Lead Lag base load common setting was invalid 153 Minimum pressure parameter was greater than setpoint 192 Lead Lag DHW demand switch setting was 193 Lead Lag Mix demand switch setting was invalid 154 Minimum pressure parameter was greater than time of day setpoint 194 Lead Lag modulation sensor setting was invalid 195 155 CH modulation rate source parameter was invalid Le
CODE DESCRIPTION 231 Lead Lag CH setpoint was invalid 232 Lead Lag CH time of day setpoint was invalid 233 LL outdoor temperature was invalid 234 Lead Lag ODR time of day setpoint was invalid 235 Lead Lag ODR time of day setpoint exceeded normal setpoint 236 Lead Lag ODR max outdoor temperature was invalid 237 Lead Lag ODR min outdoor temperature was invalid 238 CODE DESCRIPTION 274 Abnormal Recycle: Demand off during Pilot Flame Establishing Period 275 Abnormal Recycle: LCI off during
CODE DESCRIPTION CODE DESCRIPTION 304 Abnormal Recycle: ILK off during Measured Purge Time 341 Abnormal Recycle: Hardware SLO electronics 305 Abnormal Recycle: ILK off during Drive to Lightoff Rate 342 Abnormal Recycle: Hardware processor clock 343 Abnormal Recycle: Hardware AC phase 306 Abnormal Recycle: ILK off during Pre-Ignition test 344 Abnormal Recycle: Hardware A2D mismatch 307 Abnormal Recycle: ILK off during Pre-Ignition time 345 Abnormal Recycle: Hardware VSNSR A2D 308 Abnor
CODE DESCRIPTION CODE DESCRIPTION 382 Abnormal Recycle: Fan Speed Range High 482 Internal error: Safety key bit 4 was incorrect 383-450 RESERVED 483 Internal error: Safety key bit 5 was incorrect Circulator Errors 484 Internal error: Safety key bit 6 was incorrect 451 Circulator control was invalid 485 Internal error: Safety key bit 7 was incorrect 452 Circulator P-gain was invalid 486 Internal error: Safety key bit 8 was incorrect 453 Circulator I-gain was invalid 487 Internal err
CODE DESCRIPTION CODE DESCRIPTION 527 Mix circulator sensor was invalid 571 Heat exchanger high limit response was invalid 528 Mix flow control was invalid 572 Heat exchanger high limit was exceeded 529 Mix temperature was invalid 573 530 Mix sensor was invalid Heat exchanger high limit wasn't allowed due to stack limit setting 531 Mix PID setpoint was invalid 574 532 STAT may not be a Mix demand source when Remote Stat is enabled Heat exchanger high limit wasn't allowed due to stack
Servicing should only be performed by a Qualified Service Agent AIR SEPARATOR MODEL XB-1000 XB-1300 XB-1700 XB-2000 XB-1600 XB-3400 EXPANSION TANK INLET DIA. 2” 2” 2.5” 3” 3” 4” MAKE-UP WATER Figure 55.
Figure 56.
NOTES Servicing should only be performed by a Qualified Service Agent 77
NOTES 78 Servicing should only be performed by a Qualified Service Agent
NOTES Servicing should only be performed by a Qualified Service Agent 79
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.
