Service Handbook COMMERCIAL BOILERS 25589 Highway 1 McBee, SC 29101 FOR MODELS: XB/XW 1000, 1300, 1700 2000, 2600, 3400 SERIES 100/101 INSTALLATION CONSIDERATIONS - PRE SERVICE CHECKS - BOILER CONSTRUCTION OPERATION & SERVICE - TROUBLESHOOTING SERVICING SHOULD ONLY BE PERFORMED BY A QUALIFIED SERVICE AGENT PRINTED IN THE U.S.A.
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 boiler Model 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 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 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; ensure the venting has been installed per all Instruction Manual requirements.
BOILER CONTROLS Boiler 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 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 Figure 2.
Figure 3.
OPERATION AND SERVICE MODULATING FIRE OPERATION XP Boilers are modulating fire boilers. The control system modulates the firing rate of the burner to match system load by controlling the speed of the combustion blower. XP Boilers 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 from 2nd and 3rd gas family are evacuated.
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 dimensioned 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 on the XP Boiler 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 XP Boiler is a 120VAC igniter. The igniter receives power from the J5 socket on the Control Board. Normal resistance of the igniter is 40-70 ohms @ 77°F (25°C).
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'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 XP boilers use a 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 J5 socket, Terminal 6 on the Control Board to the External Spark Transformer. Spark Igniters are wearing parts, over time Spark Igniters will wear out and must be replaced as they will no longer generate enough heat to cause ignition.
GAS VALVE The 24 Volt Gas Valve on the XP Boilers is DC 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 insert the two test probes into pin 2 of the J5 Connector on the Control Board. 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’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.
AIR FILTER ASSEMBLY Figure 13. AIR FILTER ASSEMBLY Air Filter Assembly is mounted on the top panel of the XP Boilers. 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.
CONTROL PANEL ASSEMBLY Figure 14, Figure 15 on Page 23 and Figure 16 on Page 24 shows the Control Panels Assemblies for the XP Boilers. 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 control sequencing, and electric ignition function. It will also provide boiler status and error reporting.
Figure 17.
Table 3. CONTROL BOARD CONTACTS/CONNECTIONS CONNECTORS J1 J2 PINS DESCRIPTION AND RATING 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 -.
CONNECTORS J6 J7 J8 J9 PINS TERMINOLOGY DESCRIPTION AND RATING 1 LWCO Annunciator for LWCO Input. 2 Not Used 3 FLOW_SW 4 Not Used 5 Not Used 6 Not Used 7 Not Used 8 Not Used 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.
DISPLAY SYSTEM (TOUCH SCREEN DISPLAY) The Display System is a microprocessor-based touchscreen Operator Interface (OI) displays 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 but is primarily used for multiple boiler applications in a lead/lag arrangement.
Figure 19. DISPLAY CONNECTOR TERMINALS SCHEMATIC DIAGRAM Figure 20.
BOILER START UP AND OPERATIONS PRIOR TO START UP In addition to normal supplies and hand tools necessary for installing and servicing the boilers, 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. 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 Take the manifold pressure by removing the pipe plug 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. And the static to dynamic pressures may vary in the range of 2" - 5" W.C. depending on the boiler models.
CHECK/CONTROL WATER HARDNESS XW Model XP Boilers 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. Refer to Table 6 for recommend flow rate to maintain scale free operation with up to a medium water hardness. For scale free operation in hard water systems with a water hardness greater than 12 grains per gallon, a water softener must be installed and maintained. Table 6.
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 at high fire to perform the following adjustments. Start the boiler 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 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 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.
LOW FIRING RATE SETTING Set the boiler 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. This will expose the offset adjustment screw. Using a TORX® T40 or a 5 mm hex wrench, carefully adjust the low fire gas setting to achieve the CO2 level prescribed in Table 20.
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 control sequencing, and electric ignition function. It will also provide boiler status and error reporting. Multiple boilers can be joined together to heat a system instead of a single, larger burner or boiler.
Figure 27. GENERAL R7910A1138 BOILER SCHEMATIC The above figure shows two loops of heat control: Central Heating (CH), and an optional second loop for Domestic Hot Water (DHW) can be configured on each R7910A. The DHW loop transfers heat from the boiler outlet to hot water appliances in conjunction with the primary system heat loop. Priority assignment to each heat loop can be configured to specify which loop gets serviced first.
4. Storage/Shipping Temperature: -40°F to 150°F (-40°C to 66°C). 5. Humidity: • Up to 95% Relative Humidity, noncondensing at 104°F for 14 days. Condensing moisture may cause safety shutdown. 6. Vibration: 0.0 to 0.5g Continuous (V2 level). 7. Enclosure: Nema 1/IP40. 8. Approvals: Underwriters Laboratories, Inc. (UL)(cUL): Component Recognized: File No. MP268 (MCCZ). • R7910 is certified as UL372 Primary Safety Controls.
6. MAIN FLAME ESTABLISHING PERIOD. (MFEP): a. Lockout Interlock opens (if enabled). b. Pilot valve terminal is not energized. c. Main valve terminal is not energized. d. No flame present at the end of MFEP. e. Internal system fault occurred. 7. RUN PERIOD: a. No flame is present, or flame is lost (if enabled-lockout). b. Lockout Interlock opens) if enabled). c. IAS Purge and Ignition enabled and the Interlock opens. d. Pilot terminal energized (if programmed as Interrupted Pilot). e.
6. As soon as the fan-rpm is equal to the light-off rpm (or the Low Fire Switch closes), the Trial for Ignition or Pre-Ignition Time is started. 7. Pre-Ignition Time will energize the ignitor and check for flame. 8. Trial for Ignition. Specifics for timings and device actions are defined by the OEM or installer. 9. The ignition and the gas valve are switched on. 10.
LEAD LAG (LL) MASTER GENERAL OPERATION The XP Boiler is a multiple burner application and it works on the basis of the Lead Lag Operation. The XB Boiler is factory configured for Hydronic/Central Heating application, whereas the XW Boiler is factory configured for Domestic Hot Water application. The LL master coordinates the firing of its slave Burner Control Systems. To do this it adds and drops stages to meet changes in load, and it sends firing rate commands to those that are firing.
LOCAL OPERATOR INTERFACE: DISPLAY SYSTEM Figure 28. S7999B DISPLAY SYSTEM The S7999B 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 S7999B can be used to monitor an individual boiler but is primarily used for multiple boiler applications in a lead/lag arrangement. COM 2 port is available for Building Automation applications.
SPECIFICATIONS 1. Electrical Ratings: +12 VDC input, maximum of 500 mA current drain. Included Power Supply for S7999B: • Inputs: 85 to 264 VAC, 47 to 63 Hz; 120 to 370 VDC. • Output: 12 VDC; 0 to 2.1 A. • Power: 25 W. 2. Operating Temperature: 32°F to 122°F (0°C to 50°C) 3. Storage/Shipping Temperature: -40°F to 158°F (-40°C to 70°C). 4. Humidity: 85% maximum relative humidity. 5. Approvals: FCC Part 15, Class A Digital Device Underwriter’s Laboratories, Inc.
STARTING UP THE S7999B OI DISPLAY Power-up Validation The Home page will appear and the “Power” LED will be blinking 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 1 and 2 wiring connections. NOTE: An Advanced Startup screen displays for five seconds after power-up before the Home page displays. This screen allows the user to upgrade the software in the System Display and should normally be bypassed.
Figure 32.
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 boiler 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 32 on Page 47.
Figure 33. SUMMARY STATUS PAGE (HYDRONIC CONTROL) CONFIGURE BUTTON Pressing the Configure button (bottom left) on the Status page opens the Configuration page. All the required settings for the Burner are factory configured. The S7999B Configuration page does not have a “Display Setup” button. The configuration page allows the user to view and set parameters that define how the connected R7910A functions in the hydronic heating system.
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. Leaving the configuration pages ends the scope of the password. Three levels of access to Burner Control parameters are permitted. Each access level has defined rights when interfacing with configuration and status parameters within the controls.
LOGIN Pressing the Login button allows entering the password from a keyboard as shown in Figure 37. After the password is entered, the OK button is selected. The Cancel button aborts the password login. Figure 37. 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 39. SAFETY VERIFICATION Figure 40. 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 S7999B), the History button turns red. If the S7999B 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 43. EXAMPLE OF HYDRONIC HISTORY 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 46. CONTROL EXPANDED LOCKOUT DETAIL Figure 47. 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’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 48.
DIAGNOSTICS BUTTON The Diagnostics button displays analog and digital I/O status of the Burner Control. 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 51). Not all digital I/O can be displayed at the same time on the page, so a horizontal scroll bar is used to move the view left and right to show all digital I/O data. Figure 51.
SYSTEM SYNCHRONIZATION (S7999B 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 operation. POOR COMBUSTION - IGNITION FAILURE - ROUGH START/OPERATION • Ensure the correct type of fuel gas, natural gas or propane, is supplied to the boiler., see the boiler's rating label.
RESTORE GAS FLOW SETTINGS TO DEFAULT Each XP Boiler 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 boilers performance. When performing the on site Start-up, gas flow can be improperly adjusted to the point the boiler 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 124 High fire switch OFF 125 High fire switch stuck ON RECOMMENDED TROUBLESHOOTING OF LOCKOUT CODES 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. 4. Check wiring and correct any potential wiring errors.
CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF LOCKOUT CODES NOTE 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. Check wiring and correct any potential wiring errors. 2. Check High Fire Switch to assure proper function (not welded or jumpered). 3.
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 56.
Servicing should only be performed by a Qualified Service Agent MODEL XW-1000 XW-1300 XW-1700 XW-2000 XW-1600 XW-3400 INLET DIA. 2” 2” 2.5” 3” 3” 4” OUTLET DIA. 2” 2” 2.5” 3” 3” 4” DRAIN Figure 57.
NOTES
NOTES
25589 Highway 1, McBee, SC 29101 Technical Support: 800-527-1953 • Parts: 800-433-2545 • Fax: 800-644-9306 www.hotwater.
