Lochinvar KNIGHT 400 Service Manual
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Lochinvar KNIGHT 400 Service Manual

Commercial boiler
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See also: User's Information Manual , Operation & Installation Manual
KBXII-SER Rev C
Service Manual
Models: 400 - 801
This manual must only be used
WARNING
by a qualified heating installer /
service
technician.
Read
all
instructions, including this manual
and the Knight XL 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 Lochinvar KNIGHT 400

  • Page 1 KBXII-SER Rev C Service Manual Models: 400 - 801 This manual must only be used WARNING by a qualified heating installer / service technician. Read instructions, including this manual and the Knight XL 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.

  • Page 2: Table Of 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 ... 4 Freeze protection fluids ... 4 WHAT IS IN THIS MANUAL ... 5 1.

  • Page 3: Please Read Before Proceeding

     Breathing: Fresh air. Service Manual When calling or writing about the boiler NOTICE – Please have the boiler model and serial number from the boiler rating plate. Consider piping and installation when determining boiler location (see the Knight XL Installation and Operation Manual).

  • Page 4: When Servicing Boiler

    Instead, shut off the gas supply at a location external to the appliance. • Do not use this boiler if any part has been under water. The possible damage to a flooded appliance can be extensive and present numerous safety hazards. Any appliance that has been under water must be replaced.

  • Page 5: What Is In This Manual

    Service Manual Maintenance • 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 •...

  • Page 6: Service Near Boiler Piping

    Near boiler piping This piping reference is included to specify the Near Boiler Piping specific to the Knight XL. This piping scheme is important for proper operation of the SMART SYSTEM control. See the Knight XL Installation and Operation Manual for more detailed piping diagrams.

  • Page 7: The Knight Xl Display

    Service Manual Service (continued) The Knight XL 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...

  • Page 8: Control Inputs

    Service Service Control inputs SYSTEM PUMP SPEED CONTROL GAS PRESSURE SWITCH DHW THERMOSTAT ROOM THERMOSTAT / ZONE CONTROL FLOW SWITCH SYSTEM SENSOR OUTDOOR SENSOR SEQUENCER / BUILDING MANAGMENT SYSTEM LOW WATER CUTOFF O-TEMP HEAT EXCHANGER SWITCH INLET TEMPERATURE SENSOR OUTLET TEMPERATURE / HI-LIMIT SENSOR FLUE GAS SENSOR AIR PRESSURE SWITCH...

  • Page 9: Control Outputs

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

  • Page 10: General 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. The gas valve senses the amount of air flowing into the boiler and allows only the right amount of gas to flow.
  • Page 11 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.
  • Page 12 DHW boiler set point. 9. If the boiler is not part of a Cascade, and both the space heating and DHW calls for heat remain active long enough, the boiler will switch back and forth between the two heating modes until one of them is satisfied.

  • Page 13: Display Panel Menu Access

    Service Service (continued) Display panel menu access Table 1-2 Use this procedure to access menus from the display panel SCREEN BUTTON 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 Service Display panel parameter access Table 1-3 This is a typical example of accessing a parameter, shown for parameter Temperature Settings, MIN SH Setpt SCREEN BUTTON 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 Service (continued) Parameter table Table 1-4 This table lists SMART SYSTEM control module parameters and where to access them Menu Description Time and Date Software Version (read only) Temperature Units (ºC/ºF) SH Night Setback Offset SH Night Setback On Times SH Night Setback Off Times DHW Night Setback Offset DHW Night Setback On Times...
  • Page 16 Parameter table Table 1-4 (continued from previous page) This table lists SMART SYSTEM control module parameters and where to access them Menu Description DHW Boiler Set Point Tank Set Point Tank Set Point Differential DHW Boiler Offset DHW Boiler Differential...
  • Page 17 Cascade Differential Min On/Off Time Min Next On Time System Pump Delay Boiler Pump Delay DHW Pump Delay Boiler Pump Anti-Seize Delay Boiler Pump Min Voltage System Pump Type DHW Pump Anti-Seize Delay System Pump Anti-Seize Delay Service Manual User Access...

  • Page 18: Parameter Table

    Service Parameter table Table 1-4 (continued from previous page) This table lists SMART SYSTEM control module parameters and where to access them Menu Description BMS Type Volts at Min Volts at Max Rate at Min Volts Rate at Max Volts Set Point at Min Volts Set Point at Max Volts On Volts...

  • Page 19: Viewable And Changeable Control Parameters

    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.

  • Page 20: Data Logging

    The delay sets the length of time the boiler will stay in the Service Mode if no keys have been pressed before going back to its original state. This parameter can only be changed by the installer by accessing the Service Mode Delay parameter.
  • Page 21 DHW tank as a separate load, or as a zone on the primary loop. When programmed as a separate load, the boiler will turn on the DHW pump and then turn off the boiler pump when an indirect DHW demand begins. When programmed as...

  • Page 22: Outdoor Reset

    Service Outdoor Reset The option of controlling up to three (3) different outdoor resets for low outdoor temperatures is available. Outdoor (1 - 3) Low When the outdoor air temperature drops to this point, the water temperature will be at the Set point 1 at Low Outdoor Temp 1, Set point 2 at Low Outdoor Temp 2 and Set point 3 at Low Outdoor Temp 3 parameters (FIG.
  • Page 23 The control will bypass the anti-cycling time if the inlet water temperature drops too much. The control will use the inlet water temperature the boiler was at when it shut off as the starting point. If the inlet temperature drops below the temperature parameter the control will abort anti-cycling and allow the boiler to fire.
  • Page 24 Outlet Sensor. BMS Thermostat Input When controlling the boiler through the 0 - 10V BMS input or through ModBus, the boiler can be enabled one of two ways. With the BMS Thermostat Input parameter set to ACTIVE, the boiler will be enabled by closing the Heat/Loop Demand 1 input.
  • Page 25 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.

  • Page 26: Bms

    Service Manual DHW Pump Anti-Seize Delay If the boiler pump does not run for 24 hours, it will be turned on briefly to prevent it from seizing. The length of time it runs is determined by the DHW Pump Anti-Seize Delay parameter.

  • Page 27: Service Notification

    ModBus and the BMS Thermostat Input is set to INACTIVE, the On Volts parameter determines the 0 - 10V BMS input voltage at which the boiler is enabled. The minimum value is 0.5V and the maximum is 10.0V. The default value is 2.0V.

  • Page 28: Maintenance

    • Check condensate drain system • Check air vents • Test low water cutoff (if used) • Reset button (low water cutoff) • Check boiler piping (gas and water) for leaks • Operate relief valve • Shut boiler down (unless boiler...

  • Page 29: Address Reported Problems

    The boiler should be inspected annually only by a qualified service technician. In addition, the maintenance WARNING and care of the boiler designated in Table 2-1 and explained on the following pages must be performed to assure maximum boiler efficiency and reliability. Failure to service and maintain the boiler and system could result in equipment failure.

  • Page 30: Check Expansion Tank

    2. Check the cold fill pressure for the system. Verify it is correct (must be a minimum of 12 psi (82.7 kPa)). 3. Watch the system pressure as the boiler heats up (during testing) to ensure pressure does not rise too high.

  • Page 31: Check Control Settings

    4. Replace ground wires if ground continuity is not satisfactory. Check all boiler wiring 1. Inspect all boiler wiring, making sure wires are in good condition and securely attached. Check control settings 1. Set the SMART SYSTEM control module display to Parameter Mode and check all settings.

  • Page 32: Check Flame Signal

    • Follow the “To Turn Off Gas to Appliance” instructions for the boiler in Section 10 - Startup of the Installation and Operation Manual. • Do not drain the boiler unless it will be exposed to freezing temperatures. If using freeze prevention fluid in system, do not drain.

  • Page 33: Troubleshooting

    PUMPS F2 - 3.15 AMP FUSE BLOWER 5. The boiler is shipped with three (3) spare fuses in a plastic bag attached to the control module cover. 6. If necessary, replace open fuse (F3 is .80 amps, F2 is 3.15 amps and F1 is 5 amps).

  • Page 34: Table 3-1 - Troubleshooting Chart - No Display

    - Unit locked out on fault. - Unit in Shutdown Mode. - Ramp delay active. Unit Does Not Modulate - Boiler controlled by BMS. Above 50% - Flue sensor open. CAUSE • Check external line switch, fuse, or breaker. • Check position of ON/OFF switch. Turn switch to the ON position.

  • Page 35: Checking Temperature Sensors

    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.

  • Page 36: Table 3-3 - Troubleshooting Chart - Noisy System

    Clean or replace the burner as necessary. Knight XL 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: Fault Messages Displayed On Boiler Interface

    Troubleshooting Table 3-4 Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT - Either the optional manual reset low gas Gas Pressure SW pressure switch or the optional manual reset high gas pressure switch tripped. (will require a manual reset once the condition has been corrected.

  • Page 38: Corrective Action

    Troubleshooting Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION APS / HEX Temp Sw Open Either the air pressure switch contacts are (will require a manual open, or the O-temp heat exchanger switch reset once the condition has opened.
  • Page 39 Troubleshooting Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION The unit has failed to prove main burner ignition after four (4) attempts. Flame Fail Ign (cont’d) (will require a manual reset once the condition has been corrected.
  • Page 40 Troubleshooting Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION The outlet water temperature has exceeded Outlet ARHL the setting of the automatic reset high limit. Outlet MRHL (will require a manual reset once the condition has been corrected.
  • Page 41 Troubleshooting Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT Outlet MRHL (cont’d) (will require a manual The outlet water temperature has exceeded reset once the condition the setting of the manual reset high limit.
  • Page 42 Troubleshooting Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT Sensor Shorted (will require a manual reset once the condition has been Either the inlet water or outlet water corrected. Press the RESET temperature sensor has been shorted.
  • Page 43 Troubleshooting Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT Flue Sensor Fault (will require a manual reset once the condition has been The control reads the flue sensor as open corrected. Press the RESET or shorted.
  • Page 44 Troubleshooting Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT The stack temperature has exceeded the set Flue Temp High parameters for the boiler. Delta T High The temperature rise across the heat exchanger has exceeded the set parameters for the boiler.
  • Page 45 Troubleshooting Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION Rem Ctrl Flt External control is cycling too often. Parameters Progr (will require a manual reset once the condition After downloading parameters from a laptop, has been corrected.

  • Page 46: Combustion Analysis Procedure

    Troubleshooting Combustion Analysis Procedure 1. Turn the main power off to the boiler by placing the “On/ Off” switch in the OFF position. 2. Remove the flue temperature sensor from the flue pipe connection. Note: Combustion measurements will be made at this point.

  • Page 47: Gas Valve Adjustment Procedure

    Troubleshooting Gas valve adjustment procedure If adjustment of the gas valve is deemed necessary, use the following procedures: (Note: The procedures below are model specific.) Under normal operating conditions this CAUTION valve should not need adjusting. Model 400 Locate the throttle adjustment screw on the top of the gas valve, see FIG.

  • Page 48: Revision Notes

    Revision Notes: Revision A (ECO #C05747) initial release. Reflects the new model numbers for the Knight XL upgrade. Revision B (ECO #C06234) reflects changes made to the Service Notification parameter. Revision C (ECO #C07981) reflects changes made to the parameter table, parameter descriptions, updates to the troubleshooting chart, and the addition of the O-temp HEX switch.

This manual is also suitable for:

Knight 801Knight xl 501

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