Lochinvar 400 manual

Service Manual Models: 400 - 801 This manual must only be used 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 p[...]

2 Hazard definitions The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels or to important information concerning the life of the product.  DANGER  WARNING  CAUTION CAUTION NOTICE DANGER indicates an imminently hazardous situation which, if not avoided, will result [...]

Service Manual Please read before proceeding Installer – Read all instructions, including this manual and the Knight XL Installation and Operation Manual, before installing. Perform steps in the order given. User – This manual is for use only by a qualified heating installer/service technician. Refer to the Knight XL User’s Information Manual[...]

4 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 g[...]

5 What is in this manual? Service Near boiler piping • Typical system components The Knight XL display • Display panel readout, buttons and their functions Control module inputs • Control module inputs and options Control module outputs • Control module outputs and options General • How the boiler operates • How the control module opera[...]

1 Service 6 Y- S T R A I N E R (RECOMMENDED) BOILER PUMP INDIREC T DOM ESTIC HOT WA T ER T ANK SYSTEM PUMP TO FLOOR DRAIN T O F R O M F R O M S Y S T E M T O S Y S T E M DOMESTIC HOT WA TER P UM P SYSTEM SENSOR DIRT SEP ARA TOR Near boiler piping This piping reference is included to specify the Near Boiler Piping specific to the Knight XL. This pip[...]

7 1 Service (continued) NA VIGA TION DIAL The Knight XL display 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 Service Manual[...]

1 Service 8 1 Service GAS PRESSURE SW ITCH DHW THERMOSTAT ROOM THERMOSTAT / ZONE CO NTROL FLOW SW IT CH SYSTEM SENSOR OUTDOOR SENSO R SEQUENCER / BUILDING MANAGMENT SY STEM LOW VOLTAGE CONNECT ION BOARD INLET TEMPERATURE SENSOR OUTLET TEMPERATURE / HI-LIMIT SENSOR FLUE GAS SENSOR LOUVER PROVING SW IT CH FLAME SENSOR LOW W ATER CUTOF F BLOCKED DRAIN[...]

1 Service 9 1 Service (continued) LOW VOL T AGE CONNECT ION BOARD SMAR T CONTROL MODULE ALARM BELL LOUVER RELA Y RUN TI ME CONT ACTS BUILDING M ANAGEM ENT SYSTEM BOILER PUMP SYSTEM PUMP DHW PUMP IGNITOR BLOW ER GAS V AL VE DISPLA Y P ANEL PC INTERF AC E Control outputs Service Manual[...]

1 Service 10 1 Service General Operation How the boiler operates The Knight XL 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 bl[...]

1 Service 1 Service (continued) Table 1-1 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. Th[...]

1 Service 12 1 Service Table 1-1 (continued from previous page) Sequence of Operation 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 t[...]

1 Service 13 1 Service (continued) Display panel menu access Table 1-2 Use this procedure to access menus from the display panel BUTTON SCREEN STATUS OPERATION DISPLAY [SHDN] Press the RIGHT SELECT soft key [SHDN]. [YES] Press the LEFT SELECT soft key [YES]. [MENU] Press and hold the LEFT SELECT soft key [MENU] for five (5) seconds. Rotate the NAVI[...]

1 Service 14 1 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 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 ent[...]

1 Service 15 1 Service (continued) Parameter table Table 1-4 This table lists SMART SYSTEM control module parameters and where to access them Service Manual Menu Description See Page User Access Installer Access Display Modify Display Modify Time and Date 19 Yes Yes Yes Yes Software Version (read only) 19 No No Yes No Temperature Units (ºC/ºF) 19[...]

1 Service 16 1 Service Parameter table Service Manual Table 1-4 (continued from previous page) This table lists SMART SYSTEM control module parameters and where to access them Menu Description See Page User Access Installer Access Display Modify Display Modify DHW Boiler Set Point 21 No No Yes Yes Tank Set Point 21 Yes Yes Yes Yes Tank Set Point Di[...]

1 Service (continued) 17 Parameter table Table 1-4 (continued from previous page) This table lists SMART SYSTEM control module parameters and where to access them Service Manual Menu Description See Page User Access Installer Access Display Modify Display Modify Boost Temperature 23 No No Yes Yes Boost Time 23 No No Yes Yes Anti-Cycling Time 23 No [...]

1 Service 18 Parameter table Table 1-4 (continued from previous page) This table lists SMART SYSTEM control module parameters and where to access them Service Manual Menu Description See Page User Access Installer Access Display Modify 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 V[...]

19 1 Service (continued) Viewable and changeable control parameters Service Manual 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 f[...]

20 1 Service Service Manual SH1 - SH3 Differential Set Point The SH differential sets how many degrees below the offset the temperature has to drop before the boiler turns back on. This parameter can only be changed by the installer by accessing the SH1, 2 and 3 Differential Set point parameters . The range is 0°F to 60°F. The default is 20°F. D[...]

21 1 Service (continued) Service Manual DHW Settings DHW Boiler Set Point When a DHW call for heat becomes active, the control will use the DHW boiler set point to determine the firing rate of the boiler based on the boiler outlet water temperature, or system temperature when DHW is programmed as a zone. This parameter can be changed by the install[...]

22 1 Service Service Manual SET POINT A T LOW OUTDOOR TEMPERA TURE (SH1, SH2, SH3) SET POINT SET POINT A T HIGH OUTDOOR TEMPERA TURE LOW OUTDOOR TEMPERA TURE HIGH OUTDOOR TEMPERA TURE Figure 1-1 Outdoor Air Reset Curve Outdoor Reset The option of controlling up to three (3) different outdoor resets for low outdoor temperatures is available. Outdoor[...]

23 1 Service (continued) Service Manual Anti-Cycling Anti-Cycling Time Once a SH demand has been satisfied, a set amount of time must elapse before the control will respond to a new SH demand. The control will block the new heat demand and anti-cycling will be shown in the display until the time has elapsed or the water temperature drops below the [...]

24 1 Service Service Manual Figure 1-2 Ramp Delay Interval Control modes Controlling Sensor The SH controlling sensor parameter selects the sensor the control will use to regulate the boiler firing rate. This parameter is adjustable by the installer by accessing the Controlling Sensor parameter . The sensor selections are as follows: The outlet sen[...]

25 1 Service (continued) Service Manual ModBus When BMS is set to ACTIVE (see BMS Active / Inactive) and the boiler is being controlled through ModBus, set ModBus parameter to ACTIVE. Otherwise, set the ModBus parameter to INACTIVE. Note that the boiler can still be monitored by ModBus with this parameter set to INACTIVE. The default value is INACT[...]

26 1 Service 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. The range of this setting is 0 seconds to 50 minutes. The default setting is 20 seconds. System Pump Anti-Se[...]

27 1 Service (continued) Service Manual Service Name and Phone Number When a Maintenance Reminder timer or counter has expired, a Maintenance Reminder screen will appear on the display. By programming the installer’s name and phone number, this information will appear on the Maintenance Reminder Screen at that time. This can be programmed by acce[...]

2 Maintenance 28 Maintenance and annual startup Table 2-1 Service and Maintenance Schedules Service technician (see the following pages for instructions) General: • Address reported problems • Inspect interior; clean and vacuum if necessary; • Clean condensate trap and fill with fresh water • Check for leaks (water, gas, flue, condensate) ?[...]

2 Maintenance (continued) 29 Follow the Service and maintenance procedures given throughout this manual and in component literature 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 pe[...]

2 Maintenance 30 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 obstructio[...]

2 Maintenance (continued) 31 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 igniti[...]

2 Maintenance 32 Check flame signal 1. At high fire the flame signal shown on the display should be at least 10 microamps. 2. A lower flame signal may indicate a fouled or damaged flame sense electrode. If cleaning the flame sense electrode does not improve, ground wiring is in good condition, and ground continuity is satisfactory, replace the flam[...]

3 Troubleshooting 33 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 [...]

3 Troubleshooting 34 Table 3-1 Troubleshooting Chart - No Display Service Manual FAULT CAUSE CORRECTIVE ACTION No Display - No 120 vac supplied to unit. • Check external line switch, fuse, or breaker. • Check position of ON/OFF switch. Turn switch to the ON position. • Check 120 vac through the ON/OFF switch. • Check wiring harness connecti[...]

3 Troubleshooting (continued) 35 Table 3-2A - Inlet Water/System Sensor Resistance vs. Temperature Temperature Resistance Temperature Resistance 50 18,780 158 1,990 68 12,263 176 1,458 86 8,194 194 1,084 104 5,592 212 817 122 3,893 140 2,760 Table 3-2B - Outdoor Air Sensor Resistance vs. Temperature Temperature Resistance Temperature Resistance -50[...]

3 Troubleshooting 36 Table 3-3 Troubleshooting Chart - Noisy System FAULT CAUSE CORRECTIVE ACTION Noisy Operation - Supply gas problem. Natural gas pressures should be between 4 inches w.c. and 14 inches w.c. LP gas pressures should be between 8 inches w.c. and 14 inches w.c. • Refer to Section 7 - Gas Connections of the Knight XL Installation an[...]

3 Troubleshooting (continued) 37 Table 3-4 Troubleshooting Chart - Fault Messages Displayed on Boiler Interface Service Manual FAULT DESCRIPTION CORRECTIVE ACTION Gas Pressure SW (will require a manual reset once the condition has been corrected. Press the RESET button on the SMART SYSTEM display to reset.) - Either the optional manual reset low ga[...]

3 Troubleshooting 38 Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface Service Manual FAULT DESCRIPTION CORRECTIVE ACTION APS / HEX Temp Sw Open (will require a manual reset once the condition has been corrected. Press the RESET button on the SMART SYSTEM display to reset.) Either the air [...]

3 Troubleshooting (continued) 39 Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface Service Manual FAULT DESCRIPTION CORRECTIVE ACTION Flame Fail Ign (cont’d) (will require a manual reset once the condition has been corrected. Press the RESET button on the SMART SYSTEM display to reset.) [...]

3 Troubleshooting 40 Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface Service Manual FAULT DESCRIPTION CORRECTIVE ACTION Outlet ARHL The outlet water temperature has exceeded the setting of the automatic reset high limit. • Adjust the set point of the auto reset limit to a higher settin[...]

3 Troubleshooting (continued) 41 Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface Service Manual FAULT DESCRIPTION CORRECTIVE ACTION Outlet MRHL (cont’d) (will require a manual reset once the condition has been corrected. Press the RESET button on the SMART SYSTEM display to reset.) The[...]

3 Troubleshooting 42 Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface Service Manual FAULT DESCRIPTION CORRECTIVE ACTION Sensor Shorted (will require a manual reset once the condition has been corrected. Press the RESET button on the SMART SYSTEM display to reset.) Either the inlet water [...]

3 Troubleshooting (continued) 43 Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION Flue Sensor Fault (will require a manual reset once the condition has been corrected. Press the RESET button on the SMART SYSTEM display to reset.) The control reads the f[...]

3 Troubleshooting 44 Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION Flue Temp High The stack temperature has exceeded the set parameters for the boiler. • Inspect the heat exchanger. Reference page 32 of this manual for the procedure on how to clean[...]

3 Troubleshooting (continued) 45 Table 3-4 (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION Rem Ctrl Flt External control is cycling too often. • Check set point of the external control. • Check the wiring between the external control and the unit. • Replac[...]

3 Troubleshooting 46 Service Manual 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. 3. Turn the main power on to the boiler by placing the “O[...]

47 3 Troubleshooting (continued) Gas valve adjustment procedure If adjustment of the gas valve is deemed necessary, use the following procedures: ( Note: The procedures below are model specific.) Figure 3-3 Gas Valve Adjustment: Model 501 Model 501 Locate the throttle adjustment screw on top of the gas valve, see FIG. 3-3. Using a screwdriver, turn[...]

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 additio[...]