WH-SER Rev G Service Manual Models: WH 55 - 399 WARNING This manual must only be used by a qualified heating installer / service technician. Read all instructions, including this manual and the Knight Wall Mount Installation and Operation Manual, before installing. Perform steps in the order given. Failure to comply could result in severe personal injury, death, or substantial property damage. Save this manual for future reference.
Contents CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Hazard Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 PLEASE READ BEFORE PROCEEDING . . . . . . . . . . . . . 3 Handling Ceramic Fiber Materials . . . . . . . . . . . . . . . . . . . 3 When servicing boiler . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Boiler operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Boiler water . . . . . . . . . . . . . . . . . . . .
Service Manual Please read before proceeding WARNING Installer – Read all instructions, including this manual and the Knight Wall Mount Installation and Operation Manual, before installing. Perform steps in the order given. NOTICE User – This manual is for use only by a qualified heating installer/service technician. Refer to the Knight Wall Mount User’s Information Manual for your reference. Have this boiler serviced/inspected by a qualified service technician at least annually.
Service Manual Please read before proceeding When servicing boiler – • To avoid electric shock, disconnect electrical supply before performing maintenance. • To avoid severe burns, allow boiler to cool before performing maintenance. Boiler operation – • Do not block flow of combustion or ventilation air to the boiler. • Should overheating occur or gas supply fail to shut off, do not turn off or disconnect electrical supply to circulator.
Service Manual What is in this manual? Service Maintenance Near boiler piping • Service and maintenance schedules • Address reported problems • Inspect boiler area and boiler interior • Clean condensate trap • Check all piping for leaks • Check air openings • Flue vent system and air piping • Check water system • Check expansion tank • Check boiler relief valve • Inspect ignition electrode • Check ignition ground wiring • Check all boiler wiring • Check control settings • Perform start-up and checks • C
Service Manual 1 Service Near boiler piping This piping reference is included to specify the Near Boiler Piping specific to the Knight wall mount boiler. This piping scheme is important for proper operation of the SMART SYSTEM control. See the Knight Wall Mount Installation and Operation Manual for more detailed piping diagrams.
Service Manual 1 Service (continued) The Knight wall mount display NAVIGATION DIAL The information on the bottom of the display shows the functions of the two SELECT keys (on either corner), and the NAVIGATION dial (in the center): MENU = Left SELECT Key SETPOINTS = NAVIGATION Dial - Pressing Down SHDN = Right SELECT Key 7
Service Manual 1 Service Control inputs SYSTEM PUMP SPEED CONTROL GAS PRESSURE SWITCH DHW THERMOSTAT ROOM THERMOSTAT / ZONE CONTROL FLOW SWITCH LOW VOLTAGE CONNECTION BOARD SYSTEM SENSOR OUTDOOR SENSOR BUILDING MANAGEMENT SYSTEM LOW WATER CUTOFF INLET TEMPERATURE SENSOR OUTLET TEMPERATURE / HIGH LIMIT SENSOR FLUE GAS SENSOR PRESSURE SWITCH FLAME SENSOR SMART CONTROL MODULE DISPLAY PANEL PC INTERFACE 8
Service Manual 1 Service (continued) Control outputs ALARM BELL LOW VOLTAGE CONNECTION BOARD AUX.
Service Manual 1 Service General Operation How the boiler operates Access modes The Knight wall mount boiler uses an advanced stainless steel heat exchanger and an electronic control module that allows fully condensing operation. The blower pulls in gas and air and pushes flue products out of the boiler through the heat exchanger and flue piping. The control module regulates blower speed to control boiler firing rate.
Service Manual 1 Service (continued) Sequence of operation OPERATION DISPLAY 1. Upon a call for heat, the gas pressure switch(es) must be closed. 2. Once the gas pressure switch(es) are closed, the control turns on the appropriate pumps (system and boiler pumps for space heating, DHW pump for DHW). The flow switch and/or LWCO must close. 3. The control turns on power to the louver relay. The louver proving switch, air pressure switch, and blocked drain switch must close. 4.
Service Manual 1 Service Sequence of operation (continued) OPERATION 8. If the space heating call for heat is active, and the tank thermostat or sensor starts a DHW call for heat, the boiler will switch to the DHW mode. If programmed for normal DHW operation (not as a zone), the DHW pump will turn on first, then the boiler pump will turn off 2 (boiler and DHW pump operation briefly overlap to ensure flow is maintained through the unit).
Service Manual 1 Service (continued) Display panel menu access Table 1-2 Use this procedure to access menus from the display panel BUTTON SCREEN STATUS [SHDN] [YES] [MENU] OPERATION DISPLAY Press the RIGHT SELECT soft key [SHDN]. Press the LEFT SELECT soft key [YES]. Press and hold the LEFT SELECT soft key [MENU] for five (5) seconds. Rotate the NAVIGATION dial clockwise until 5 is displayed (first digit on the left). Press the NAVIGATION dial to select the next digit.
Service Manual 1 Service Display panel parameter access Table 1-3 This is a typical example of accessing, adjusting, and saving a parameter, shown for parameter Temperature Settings, MIN SH Setpt BUTTON SCREEN STATUS OPERATION DISPLAY This example shows how to access parameter Temperature Settings. The first display shown is at the beginning of the menu listings, after entering the installer access code. Rotate the NAVIGATION dial counterclockwise until the arrow (>) is next to TEMPERATURE SETTINGS.
Service Manual 1 Service (continued) Parameter table Table 1-4 This table lists SMART SYSTEM control module parameters and where to access them FUNCTIONS DATA LOGGING TEMPERATURE SETTINGS GENERAL Menu Description User Access See Page Display Modify Installer Access Display Modify Time and Date 19 Yes Yes Yes Yes Software Version (read only) 19 No No Yes No Temperature Units (ºC/ºF) 19 Yes Yes Yes Yes SH Night Setback Offset 19 No No Yes Yes SH Night Setback On Times 19
Service Manual 1 Service Parameter table Table 1-4 (continued from previous page) This table lists SMART SYSTEM control module parameters and where to access them OUTDOOR RESET DHW SETTINGS Menu 16 Description User Access See Page Display Modify Installer Access Display Modify DHW Boiler Set Point 21 No No Yes Yes Tank Set Point 21 Yes Yes Yes Yes Tank Set Point Differential 21 No No Yes Yes DHW Boiler Offset 21 No No Yes Yes DHW Boiler Differential 21 No No Yes Yes
Service Manual 1 Service (continued) Parameter table Table 1-4 (continued from previous page) This table lists SMART SYSTEM control module parameters and where to access them CIRCULATION PUMPS CONTROL MODES ANTI-CYCLING OUTDOOR RESET Menu Description User Access See Page Display Modify Installer Access Display Modify Boost Temperature 23 No No Yes Yes Boost Time 23 No No Yes Yes Anti-Cycling Time 23 No No Yes Yes Anti-Cycling Override Differential 23 No No Yes Yes Ramp
Service Manual 1 Service Parameter table Table 1-4 (continued from previous page) This table lists SMART SYSTEM control module parameters and where to access them SERVICE NOTIFICATION BMS Menu 18 Description User Access See Page Display Modify Installer Access Display Modify BMS Type 26 No No Yes Yes Volts at Min 26 No No Yes Yes Volts at Max 26 No No Yes Yes Rate at Min Volts 26 No No Yes Yes Rate at Max Volts 26 No No Yes Yes Set Point at Min Volts 27 No No Ye
Service Manual 1 Service (continued) Viewable and changeable control parameters CAUTION Before changing parameters, note the settings so that the unit can be returned to its original operating parameters. General Time and Date The control uses an internal clock for the night setback feature and for logging of events. For these features to work correctly, the clock must be set when the boiler is first installed or anytime the boiler has been powered off for more than four (4) hours.
Service Manual 1 Service To save any changes and return to the Home Screen, press the RIGHT SELECT [HOME] key. To return to the Status Screen without saving the changes, press the LEFT SELECT [EXIT] key. Display Timeout This is the time in which the display remains illuminated. The range is 10 seconds to 10 minutes. The default is 3 minutes. Temperature Settings CAUTION Mixing valves are required for the protection of any low temperature loops.
Service Manual 1 Service (continued) Freeze Protection Burner On If running the pumps does not prevent the inlet temperature from falling closer to freezing, the SMART SYSTEM control will fire the burner at low fire. The installer can adjust the temperature at which the burner fires by adjusting the Freeze Protection Burner On parameter. The minimum setting is -3°F (-19°C), and the maximum setting is 45°F (7.2°C). The default setting is 37°F (2.8°C).
Service Manual 1 Service Outdoor Reset Knight Wall Hung boilers are equipped with outdoor reset, a feature that saves energy by reducing the boiler water temperature as the heating load decreases. In accordance with the United States Energy Policy and Conservation Act, boilers with inputs less than 300,000 Btu/hr must use either outdoor air reset or an external energy management system. To use the outdoor reset feature, the outdoor sensor provided with the boiler must be properly installed.
Service Manual 1 Service (continued) Outdoor Air Shutdown Differential (SH1 - SH3) Boost Time The outdoor air shutdown differential parameter is the number of degrees below Outdoor Air Shutdown SH1, SH2, and SH3 parameters the outdoor air temperature must go before the boiler will respond to a SH demand. These parameters can be changed by the installer by accessing the Outdoor Air Shutdown Differential SH1, SH2, and SH3 parameters. The temperature range of this parameter is 0°F (0°C) to 54°F (30°C).
Service Manual 1 Service Ramp Settings NOTICE Please note that the brackets ([]) denote screen status. The SMART SYSTEM control can be programmed to limit the firing rate for a fixed period of time at the start of a space heating demand. There are six (6) possible limits, each with their own time delay. The first limit applies as soon as the burner starts. Once its time delay expires, the second limit is applied and its timer begins.
Service Manual 1 Service (continued) The other Cascade divider method is Efficiency Optimization, designated as EFF in the menu. This method is used, as the name implies, when it is desired to have the most efficient system. When the first boiler reaches a certain rate (default = 90%), it lowers its rate to 45% and turns on the next boiler at 45%. The two (2) boilers then modulate at the same rate.
Service Manual 1 Service Boiler Pump Delay The SH pump delay parameter sets the length of time the boiler pump will run after a SH demand has been satisfied. This parameter is adjustable by the installer by accessing the Boiler Pump Delay parameter. The time range for this parameter is 0.1 second to 40 minutes. The default time is 30 seconds. DHW Pump Delay The DHW pump delay parameter sets the length of time the DHW pump (if connected) will run after a DHW demand has been satisfied.
Service Manual 1 Service (continued) Set Point at Minimum Volts Service Notification Cycles When programmed for BMS control through the 0 - 10V BMS input or through ModBus and the BMS Type is programmed as SETPOINT, the set point represented by the Volts at Minimum parameter is set by the Set point at Minimum Volts parameter. The minimum value is 32°F (0°C) and the maximum is the Set Point at Maximum Volts setting. The default value is 70°F (21°C).
Service Manual 2 Maintenance Maintenance and annual startup Table 2-1 Service and Maintenance Schedules Service technician (see the following pages for instructions) Owner maintenance (see the Knight Wall Mount User’s Information Manual for instructions) General: • Address reported problems • Inspect interior; clean and vacuum if necessary; • Check boiler area Daily • Check pressure/temperature gauge • Clean condensate trap and fill with fresh water ANNUAL START-UP • Check for leaks (water, gas
Service Manual 2 Maintenance (continued) Follow the Service and maintenance procedures given throughout this manual and in component literature WARNING shipped with the boiler. Failure to perform the service and maintenance could result in damage to the boiler or system. Failure to follow the directions in this manual and component literature could result in severe personal injury, death, or substantial property damage.
Service Manual 2 Maintenance Flue vent system and air piping 1. Visually inspect the entire flue gas venting system and air piping for blockage, deterioration or leakage. Repair any joints that show signs of leakage. Verify that air inlet pipe is connected and properly sealed. 2. Verify that boiler vent discharge and air intake are clean and free of obstructions.
Service Manual 2 Maintenance (continued) Inspect ignition and flame sense electrodes 1. Remove the ignition and flame sense electrodes from the boiler heat exchanger access cover. 2. Remove any deposits accumulated on the ignition/flame sense electrode using sandpaper. If the electrodes cannot be cleaned satisfactorily, replace with new ones. 3. Replace ignition/flame sense electrode, making sure gasket is in good condition and correctly positioned. Check ignition ground wiring 1.
Service Manual 2 Maintenance Review with owner Oiled bearing circulators 1. Review the Knight Wall Mount User’s Information Manual with the owner. 1. The circulator shipped with the Knight wall mount boiler is water-lubricated. No oiling is required. 2. Emphasize the need to perform the maintenance schedule specified in the Knight Wall Mount User’s Information Manual (and in this manual as well). 2. Check other circulators in the system.
Service Manual 3 Troubleshooting WARNING WARNING Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. Always disconnect power to the boiler before servicing. Failure to comply could result in severe personal injury, death, or substantial property damage. Never jumper (bypass) any device except for momentary testing as outlined in the Troubleshooting chart. Severe personal injury, death, or substantial property damage can result.
Service Manual 3 Troubleshooting Table 3-1 Troubleshooting Chart - No Display FAULT CAUSE - No 120 vac supplied to unit. CORRECTIVE ACTION • Check external line switch, fuse, or breaker. • Check 120 vac. • Check wiring harness ribbon cable connection between display board and main control board. Connect harness at both points. No Display - Bad display board. • Replace board. - Bad main control board. • Replace the main control board. - Blown fuse.
Service Manual 3 Troubleshooting (continued) Checking temperature sensors The boiler temperature sensors (inlet water, outlet water, system water, flue, and outdoor air) are all resistance type devices. The following tables show the correct values for the sensors at various temperatures. Use an ohmmeter to read the resistance of the sensor at a known temperature.
Service Manual 3 Troubleshooting Table 3-3 Troubleshooting Chart - Noisy System FAULT CAUSE CORRECTIVE ACTION - Supply gas problem. Natural gas • Refer to Section 7 - Gas Connections of the Knight Wall pressures should be between 4 inches w.c. Mount Boiler Installation and Operation Manual for and 14 inches w.c. LP gas pressures detailed information concerning the gas supply. should be between 8 inches w.c. and 14 inches w.c. Noisy Operation - Gas/air mixture problem.
Service Manual 3 Troubleshooting (continued) Table 3-4 Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION Gas Pressure SW (will require a manual reset once the condition The gas pressure switch contacts on the has been corrected. Press Low Voltage Connection Board are open. the RESET button on the SMART SYSTEM display to reset.) CORRECTIVE ACTION • Check for a loose or misplaced jumper on the Low Voltage Connection Board.
Service Manual 3 Troubleshooting Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION • Check wiring harness connection at the gas valve and at the main control board. • Inspect spark electrode and associated wiring for damage and connection. Reference page 31 of this manual for removal and cleaning procedures. Replace if necessary. • Check for proper electrical grounding of the unit.
Service Manual 3 Troubleshooting (continued) Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION • Check wiring harness connection at the gas valve and at the main control board. • Inspect spark electrode and associated wiring for damage and connection. Reference page 31 of this manual for removal and cleaning procedures. Replace if necessary. • Check for proper electrical grounding of the unit.
Service Manual 3 Troubleshooting Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION • Adjust the set point of the auto reset limit to a higher setting up to a maximum of 200°F. Reference Section 10 - Operating Information of the Installation and Operation Manual for adjusting procedures. • Verify that the system is full of water and that all air has been properly purged from the system.
Service Manual 3 Troubleshooting (continued) Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT Outlet MRHL (continued) DESCRIPTION The outlet water temperature has exceeded the setting of the manual reset high limit. CORRECTIVE ACTION • If the system pump is a variable speed pump, ensure that the system flow is not less than the boiler flow.
Service Manual 3 Troubleshooting Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION Outlet Sensor Fault (will require a manual reset once the condition The control reads the outlet sensor as open has been corrected. Press or shorted. the RESET button on the SMART SYSTEM display to reset.) • Check wiring to sensor. Make sure wiring is connected and not damaged. Reconnect / repair wiring if necessary.
Service Manual 3 Troubleshooting (continued) Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION • Inspect the heat exchanger. Reference page 32 of this manual for the procedure on how to clean the flue side of the heat exchanger. Flue Temp High The stack temperature has exceeded the set parameters for the boiler. • Inspect the flue sensor and associated wiring.
Service Manual 3 Troubleshooting Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION • Verify that the system is full of water and that all air has been properly purged from the system. • Verify that the boiler is piped properly into the heating system. Refer to Section 6 - Hydronic Piping of the Knight Wall Mount Installation and Operation Manual the proper piping methods for the Knight wall mount boiler.
Service Manual 3 Troubleshooting (continued) Combustion Analysis Procedure Table 3-6 Flue Products 1. Turn the main power off to the boiler. Natural Gas 2. Remove the flue temperature sensor from the flue pipe connection. Note: Combustion measurements will be made at this point. Propane CO2 O2 CO2 O2 8.0% - 10% 3.0% - 6.5% 10.0% - 11% 4.1% - 5.4% 3. Turn the main power on to the boiler. 4. Place the boiler into the active position by pressing the RIGHT SELECT [ON] key (see page 7). 5.
Service Manual 3 Troubleshooting Gas valve adjustment procedure If adjustment of the gas valve is deemed necessary, use the following procedures: Locate the throttle adjustment screw on the side of the venturi valve (FIG. 3-2). Using a screwdriver, turn the screw a 1/4 turn clockwise to decrease CO2 levels or a 1/4 turn counterclockwise to increase CO2 levels. After performing one adjustment on the valve, follow the Combustion Analysis Procedure on page 45 of this manual to measure the combustion.
NOTES 47
Revision Notes: Revision A (ECO #C06854) initial release. Revision B (ECO #C08645) reflects additional cleaning and inspection instructions for the condensate trap (page 29). Revision C (ECO #C09197) reflects updates made to the SMART SYSTEM control (ECR #R04523). Revision D (ECO #C09843) reflects the addition of the new condensate trap pipe (R04984). Revision E (ECO #C10143) reflects the removal of the “GV/RELAY FAIL” FAULT (ECR #R05239) and updates made to the ignition timing information.
