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Knight WH 55 Service Manual

Wall mount boiler
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See also: User's Information Manual
WH-SER Rev D
Service Manual
Models: WH 55 - 399
This manual must only be
WARNING
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.

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Summary of Contents for Knight WH 55

  • Page 1 WH-SER Rev D Service Manual Models: WH 55 - 399 This manual must only be WARNING 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.

  • Page 2: Table Of Contents

    Table 3-6 - Flue Products ......45 The Knight Wall Mount Display ..... 7 Gas Valve Adjustment Procedure .

  • Page 3: Please Read Before Proceeding

    Installer – Read all instructions, When calling or writing about the boiler WARNING NOTICE including this manual and the Knight – Please have the boiler model and serial Wall Mount Installation and Operation number from the boiler rating plate. Manual, before installing. Perform steps Consider piping and installation when in the order given.

  • Page 4: When Servicing Boiler

    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.

  • Page 5: What Is In This Manual

    • Service and maintenance schedules • Address reported problems • Typical system components • Inspect boiler area and boiler interior The Knight wall mount boiler display • Clean condensate trap • Check all piping for leaks • Display panel readout, buttons and their functions •...

  • Page 6: Service Near Boiler Piping

    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.

  • Page 7: The Knight Wall Mount Display

    Service Manual Service 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...

  • Page 8: Control Inputs

    Service Manual Service Service Control inputs SYSTEM PUMP SPEED CONTROL GAS PRESSURE SWITCH DHW THERMOSTAT ROOM THERMOSTAT / ZONE CONTROL LOW VOLTAGE CONNECTION FLOW SWITCH BOARD SYSTEM SENSOR OUTDOOR SENSOR BUILDING MANAGEMENT SYSTEM LOW WATER CUTOFF INLET TEMPERATURE SENSOR OUTLET TEMPERATURE / HIGH LIMIT SENSOR FLUE GAS SENSOR PRESSURE SWITCH...

  • Page 9: Control Outputs

    Service Manual Service Service (continued) Control outputs ALARM BELL LOW VOLTAGE AUX. DEVICE RELAY CONNECTION BOARD RUN TIME CONTACTS BUILDING MANAGEMENT SYSTEM BOILER PUMP SYSTEM PUMP DHW PUMP IGNITOR BLOWER SMART CONTROL MODULE GAS VALVE DISPLAY PANEL PC INTERFACE...

  • Page 10: General Operation

    How the boiler operates Access modes User The Knight wall mount boiler uses an advanced stainless steel heat exchanger and an electronic control module that allows The user can adjust space heating and tank target temperatures fully condensing operation. The blower pulls in gas and air by pressing the NAVIGATION dial when “SETPOINTS”...
  • Page 11 Service Manual Service 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).

  • Page 12: Sequence Of Operation

    Service Manual Service Service Sequence of operation (continued) OPERATION DISPLAY 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 seconds later.

  • Page 13: Display Panel Menu Access

    Service Manual Service Service (continued) Display panel menu access Table 1-2 Use this procedure to access menus from the display panel SCREEN BUTTON OPERATION DISPLAY STATUS [SHDN] Press the RIGHT SELECT soft key [SHDN]. [YES] Press the LEFT SELECT soft key [YES]. Press and hold the LEFT SELECT soft key [MENU] [MENU] for five (5) seconds.

  • Page 14: Display Panel Parameter Access

    Service Manual Service 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 SCREEN BUTTON OPERATION DISPLAY STATUS 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.

  • Page 15: Parameter Table

    Service Manual Service Service (continued) Parameter table Table 1-4 This table lists SMART SYSTEM control module parameters and where to access them User Access Installer Access Menu Description Page Display Modify Display Modify Time and Date Software Version (read only) Temperature Units (ºC/ºF) SH Night Setback Offset SH Night Setback On Times...
  • Page 16 Service Manual Service Service Parameter table Table 1-4 (continued from previous page) This table lists SMART SYSTEM control module parameters and where to access them User Access Installer Access Menu Description Page Display Modify Display Modify DHW Boiler Set Point Tank Set Point Tank Set Point Differential DHW Boiler Offset...
  • Page 17 Service Manual Service (continued) Parameter table Table 1-4 (continued from previous page) This table lists SMART SYSTEM control module parameters and where to access them User Access Installer Access Menu Description Page Display Modify Display Modify Boost Temperature Boost Time Anti-Cycling Time Anti-Cycling Override Differential Ramp Delay...
  • Page 18 Service Manual Service Parameter table Table 1-4 (continued from previous page) This table lists SMART SYSTEM control module parameters and where to access them User Access Installer Access Menu Description Page Display Modify Display Modify BMS Type Volts at Min Volts at Max Rate at Min Volts Rate at Max Volts...

  • Page 19: Viewable And Changeable Control Parameters

    Service Manual Service (continued) Viewable and changeable control parameters Before changing parameters, note the Space Heating (SH) and Domestic Hot Water (DHW) CAUTION settings so that the unit can be returned to Night Setback On Times its original operating parameters. This is the time in which the SH Night Setback Offset becomes General active.

  • Page 20: Temperature Settings

    Service Manual Service 3-Way Valve Time To save any changes and return to the Home Screen, press the RIGHT SELECT [HOME] key. To return to the Status The optional Lochinvar Multi-Temperature Loop Control Screen without saving the changes, press the LEFT SELECT Board (MTLCB) can be used to control the supply temperature [EXIT] key.
  • Page 21 The default value is 125°F (52°C). DHW Type Tank Set Point Differential This parameter determines whether the Knight wall mount When a tank sensor is installed, the tank temperature must boiler treats the indirect DHW tank as a separate load, or as a drop this amount below the tank set point (DHW Tank zone on the primary loop.

  • Page 22: Outdoor Reset

    Service Manual Service Service Outdoor Reset Set Point (1 - 3) at Low Outdoor Temperature When the outdoor air temperature drops to the Outdoor The option of controlling up to three (3) different outdoor (1 - 3) Low parameters, the calculated set point will be at resets for low outdoor temperatures is available.
  • Page 23 Service Manual Service (continued) Outdoor Air Shutdown Differential (SH1 - SH3) Boost Time The outdoor air shutdown differential parameter is the The boost time parameter sets the amount of time that must number of degrees below Outdoor Air Shutdown SH1, SH2, elapse with a SH demand before the water temperature calculated and SH3 parameters the outdoor air temperature must go set point will be increased.
  • Page 24 Service Manual Service Service Ramp Settings The set point or modulation of the boiler may be controlled Please note that the brackets ([]) denote NOTICE through the 0 - 10V BMS input or through ModBus. When the screen status. BMS parameter is set to INACTIVE, the 0 - 10V input will be ignored.

  • Page 25: Circulation Pumps

    Service Manual Service (continued) The other Cascade divider method is Efficiency Optimization, designated as EFF in the menu. This method is used, as the Minimum On/Off Time name implies, when it is desired to have the most efficient In order to prevent units in a Cascade from short cycling, system.
  • Page 26 Service Manual Service Boiler Pump Delay DHW Blocks Sys Pump When the indirect DHW tank is connected as a zone on the The SH pump delay parameter sets the length of time the primary loop, the DHW Blocks Sys Pump parameter tells the boiler pump will run after a SH demand has been satisfied.
  • Page 27 Service Manual Service (continued) Set Point at Minimum Volts Service Notification Cycles When programmed for BMS control through the 0 - 10V BMS When the boiler control determines that a scheduled input or through ModBus and the BMS Type is programmed as service is due based on the number of boiler cycles, the SETPOINT, the set point represented by the Volts at Minimum boiler display will turn yellow and a new status screen...

  • Page 28: Maintenance

    Maintenance Maintenance and annual startup Table 2-1 Service and Maintenance Schedules Owner maintenance Service technician (see the Knight Wall Mount User’s Information (see the following pages for instructions) Manual for instructions) General: • Address reported problems • Check boiler area •...

  • Page 29: Address Reported Problems

    2. Verify that air intake area is free of any of the contaminants listed in Section 1 of the Knight Wall Mount Installation and Operation Manual. If any of these are present in the boiler intake air vicinity, they must be removed.

  • Page 30: Check Expansion Tank

    Tanks may be open, closed or diaphragm or bladder may result. If no water flows, valve is type. See Section 6 - Hydronic Piping of the Knight Wall inoperative. Shut down the boiler until a Mount Installation and Operation Manual for suggested new relief valve has been installed.

  • Page 31: Check Burner Flame

    1. Start boiler and perform checks and tests specified flame sense electrode. If cleaning the flame sense in Section 10 - Start-up of the Knight Wall Mount electrode does not improve, ground wiring is in good Installation and Operation Manual.

  • Page 32: Cleaning Boiler Heat Exchanger

    Service Manual Maintenance Review with owner Oiled bearing circulators 1. The circulator shipped with the Knight wall mount boiler 1. Review the Knight Wall Mount User’s Information is water-lubricated. No oiling is required. Manual with the owner. 2. Check other circulators in the system. Oil any circulators 2.

  • Page 33: Troubleshooting

    (LP) with gas flowing (verify during boiler inspection. startup) 8. Restore power to the boiler at the external line switch and verify boiler operation (Section 10 - Start-up in the Knight Wall Mount Installation and Operation Manual) after completing boiler service.

  • Page 34: Corrective Action

    Service Manual Troubleshooting Table 3-1 Troubleshooting Chart - No Display FAULT CAUSE CORRECTIVE ACTION - No 120 vac supplied to unit. • Check external line switch, fuse, or breaker. • Check 120 vac. • Check wiring harness ribbon cable connection between display board and main control board.

  • Page 35: Checking Temperature Sensors

    It is important to note that the flue and outlet water sensors have two temperature sensing devices in one housing. These devices are designated as S1a/S1b, outlet sensor and S3a/S3b, flue sensor. Please reference the wiring diagram in the Knight Wall Mount Installation and Operation Manual for correct terminal location.
  • Page 36 Clean or replace the burner as necessary. - Low water flow through the heat exchanger. • Refer to Section 6 - Hydronic Piping of the Knight Wall Mount Boiler Installation and Operation Manual for minimum flow rates. Verify that the boiler is piped in a primary/secondary fashion and that the boiler and system pump are running on a call for heat.
  • Page 37 • Air intake lengths exceed the maximum allowed lengths. Refer to Section 3 - General Venting of the Knight Wall Mount Installation and Operation Manual Air Pressure SW for proper lengths. (will require a manual •...
  • Page 38 4 - 14 inches w.c. and LP gas pressures should be between 8 - 14 inches w.c. Refer to Section 7 - Gas Connections of the Knight Wall Mount Boiler Installation and Operation Manual for detailed information concerning the gas supply.
  • Page 39 4 - 14 inches w.c. and LP gas pressures should be between 8 - 14 inches w.c. Refer to Section 7 - Gas Connections of the Knight Wall Mount Boiler Installation and Operation Manual for detailed information concerning the gas supply.
  • Page 40 Refer to Section 6 - Hydronic Piping of the Knight Wall Mount Installation and Operation Manual for the proper piping methods for the Knight wall mount boiler. • Check 120 vac to boiler pump motor on a call for The outlet water temperature has exceeded heat.
  • Page 41 • Vent/air intake lengths exceed the maximum allowed lengths. Refer to Section 3 - General Venting of the Knight Wall Mount Installation and Operation Manual for proper lengths. Fan Speed • Check for obstruction or blockage in the vent/air intake pipes or at terminations.
  • Page 42 Service Manual Troubleshooting Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION Inlet Sensor • Check wiring to sensor. Make sure wiring is Fault connected and not damaged. Reconnect / repair wiring if necessary.
  • Page 43 • Verify that the boiler pump is set to the proper speed or that the pump is the proper size. Reference Section 6 - Hydronic Piping of the Knight Wall Mount Boiler Installation and Operation Manual for boiler pump specifications.
  • Page 44 • Verify that the boiler pump is set to the proper speed or that the boiler pump is the proper size. Reference Section 6 - Hydronic Piping of the Knight Wall Mount Boiler Installation and Operation Manual for boiler pump specifications.

  • Page 45: Combustion Analysis Procedure

    Table 3-5 Troubleshooting Chart - Combustion Levels POSSIBLE CAUSE CORRECTIVE ACTION • Refer to Section 3 - General Venting of the Knight Wall Mount Installation and Operation Vent/Air Intake Length Manual for the proper venting and air intake methods for the Knight wall mount boiler.

  • Page 46: Gas Valve Adjustment Procedure

    Service Manual 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 CO levels or a 1/4 turn counterclockwise to increase CO...
  • Page 47 NOTES...

  • Page 48: Revision Notes

    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).

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