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FBII-SER Rev B
Service Manual
Models:
751 - 2001
This manual must only be
WARNING
used by a qualified heating
installer / service technician.
Read
all
instructions,
including this manual and
the Crest 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 Crest Audio FBN0751
- Page 1 FBII-SER Rev B Service Manual Models: 751 - 2001 This manual must only be WARNING used by a qualified heating installer / service technician. Read instructions, including this manual and the Crest Installation and Operation Manual, before installing. Perform steps in the order given.
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Page 2: Table Of Contents
Contents CONTENTS ................ 2 2. MAINTENANCE Maintenance and Annual Startup ........ 31-36 Hazard Definitions .............. 2 PLEASE READ BEFORE PROCEEDING ......3 3. TROUBLESHOOTING Before Troubleshooting ............ 37 Handling Ceramic Fiber Materials ........3 Check Control Module Fuses .......... 37 When servicing boiler ........... -
Page 3: Please Read Before Proceeding
Service Manual Please read before proceeding Installer – Read all instructions, including When calling or writing about the boiler WARNING NOTICE this manual and the Crest Installation – Please have the boiler model and serial and Operation Manual, before installing. number from the boiler rating plate. -
Page 4: Boiler Piping
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 Manual What is in this manual? Service Maintenance Near boiler piping • Service and maintenance schedules • Address reported problems • Typical system components • Inspect boiler area and boiler interior The Crest boiler display • Clean condensate trap •... -
Page 6: Service
Service Manual Service Boiler piping This piping reference is included to specify the Boiler Piping specific to the Crest boiler. This piping scheme is important for proper operation of the SMART TOUCH control. See the Crest Installation and Operation Manual for more detailed piping diagrams. -
Page 7: Smart Touch Display (Home Screen)
Service Manual Service (continued) The Home Screen displays status, modulation rate, outlet water temperature, inlet water temperature, flue temperature, system supply temperature, system return temperature, outdoor air temperature, and hot water generator tank temperature. The boiler can be started and stopped by pressing the ON/OFF button. The Boiler Status Screen and Main Menu Screen can be accessed by pressing the appropriate button. -
Page 8: Control Inputs
Service Manual Service Service Control inputs HWG THERMOSTAT / SENSOR ENABLING DEVICE CASCADE LOW VOLTAGE CONNECTION LOUVER PROVING SWITCH BOARD SYSTEM SENSOR - SUPPLY SYSTEM SENSOR - RETURN OUTDOOR SENSOR MODBUS BOARD SEQUENCER / BUILDING MANAGEMENT SYSTEM AUX SWITCH 1 & 2 SMART CONTROL 0-10 INPUT FROM MODULE... -
Page 9: Control Outputs
Service Manual Service Service (continued) Control outputs 0-10V OUTPUT TO BOILER PUMP ALARM CONTACTS LOW VOLTAGE CONNECTION LOUVER RELAY BOARD RUN TIME CONTACTS BOILER RATE OUTPUT SEQUENCER / BUILDING MANAGEMENT SYSTEM LINE VOLTAGE TERMINAL BOILER PUMP STRIP CONTACTOR SYSTEM PUMP CONTACTOR HWG PUMP CONTACTOR... -
Page 10: General Operation
Service Manual Service General Operation Figure 1-1 Home Screen How the boiler operates The Crest uses an advanced stainless steel heat exchanger and electronic control module that allows fully condensing operation. The blower pulls in air and pushes flue products out of the boiler through the heat exchanger and flue piping. - Page 11 Service Manual Service (continued) Saving parameters (reference the Parameter Table - Figure 1-4 Setup Screen Table 1B on pages 13 - 17 of this manual) To adjust and save parameters (reference FIG. 1-5): To change a parameter, use the arrows next to the parameter list on the Menu Screen to highlight the desired parameter, then press SELECT.
- Page 12 Service Manual Service Table 1A Sequence of Operation Sequence of operation Note: This unit is equipped with two (2) gas train systems. Gas Train 1 will fire first. If the demand cannot be met by the first gas train, the second gas train (Gas Train 2) will fire. Upon a call for heat, the control turns on the appropriate pumps (system and boiler pumps for a space heating call, HWG pump for a hot water generator call).
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Page 13: Parameter Table
Service Manual Service Service (continued) Parameter table Table 1B This table lists SMART TOUCH control module parameters and where to access them User Installer Default Parameter Name Menu Item Page (as shown on the LCD screen) Value Value Value Access Access Clock Date... - Page 14 Service Manual Service Parameter table Table 1B (continued from previous page) This table lists SMART TOUCH control module parameters and where to access them User Installer Default Parameter Name Menu Item Page (as shown on the LCD screen) Value Value Value Access Access...
- Page 15 Service Manual Service (continued) Parameter table Table 1B (continued from previous page) This table lists SMART TOUCH control module parameters and where to access them User Installer Default Parameter Name Menu Item Page (as shown on the LCD screen) Value Value Value Access...
- Page 16 Service Manual Service Parameter table Table 1B (continued from previous page) This table lists SMART TOUCH control module parameters and where to access them User Installer Default Parameter Name Menu Item Page (as shown on the LCD screen) Value Value Value Access Access...
- Page 17 Service Manual Service (continued) Parameter table Table 1B (continued from previous page) This table lists SMART TOUCH control module parameters and where to access them User Installer Default Parameter Name Menu Item Page (as shown on the LCD screen) Value Value Value Access...
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Page 18: Viewable And Changeable Control Parameters
Service Manual Service Viewable and changeable control parameters See Table 1B on pages 13 - 17 of this manual for parameter references listed in this section. The parameter NOTICE references listed in this section will not appear on the LCD screen. Before changing parameters, note the SH Offset CAUTION... - Page 19 Service Manual Service (continued) C: Outdoor Reset HWG Minimum User Set Point SH Set Point at Low Outdoor Temperature This setting controls the minimum user set point for the tank temperature. The installer can adjust this by accessing When the outdoor air temperature drops to the Low Outdoor parameter B10.
- Page 20 Service Manual Service Outdoor Air Shutdown Differential Shift OA Reset Curve The outdoor air shutdown differential parameter is the The shift reset curve parameter shifts the actual set point above number of degrees below parameter C5 the outdoor air or below the calculated set point by the number of degrees in temperature must go before the boiler will respond to a SH this parameter.
- Page 21 Service Manual Service (continued) E: BMS BMS Set Point at Maximum Volts When programmed for BMS control through the 0 - 10V BMS BMS (Active / Inactive) input or through ModBus and the BMS Type is programmed as The set point or modulation of the boiler may be controlled SETPOINT, the set point represented by the Volts at Maximum through the 0 - 10V BMS input or through ModBus.
- Page 22 Service Manual Service HWG Rate Limiting Freeze Protection Burner On This parameter determines the maximum rate to be used when If running the pumps does not prevent the inlet heating a HWG tank. This setting may be used when the tank temperature from falling closer to freezing, the SMART TOUCH control will fire the burner at low fire if in the ON is unable to accept all of the BTU’s available from the boiler.
- Page 23 Service Manual Service (continued) J: Cascade Modulation Factor Cascade Active / Inactive The modulation factor is used to slow down the aggressiveness of the temperature regulation routine. This can be useful in The boiler is part of a group of units sequenced together. The systems with low system flow, or in Cascade systems with more designated Leader unit determines the total output needed boiler capacity than the system needs.
- Page 24 Service Manual Service The two (2) boilers then modulate at the same rate. As the Rate % to Switch on Next Boiler calculated load increases further and both boilers ramp up When the Cascade is programmed in the Efficiency to 80%, it lowers the rate of the first two (2) boilers to 53% Optimization Mode, the currently running boilers must ramp and brings the next boiler on at 53%.
- Page 25 Service Manual Service (continued) K: Pumps HWG Pump Anti-Seize Delay Boiler Pump 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 The SH pump delay parameter sets the length of time the boiler runs is determined by parameter K8.
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Page 26: Cascade Screen
Service Manual Service Cascade Screen Figure 1-8 Cascade Screen The Cascade Screen provides the status of the Cascade System. This screen is only accessible when the boiler is the Leader of an active Cascade. There are multiple items displayed on the Cascade Screen. Along the top of the screen is the Cascade status bar. This bar will show information related to the current status and operation of the Cascade, as well as any blockings or lockouts. -
Page 27: Graph Screen
Service Manual Service (continued) Graph Screen The Graph Screen consists of two (2) different screens. The First screen is the Parameter Selection Screen. By pressing the up and down arrow keys the desired parameter can be selected. When the SELECT button is pressed the parameter will appear in the bottom half of the fi... -
Page 28: History Screen
Service Manual Service History Screen The History Screen shows the status of various counters and faults. Within the History Screen there are three separate screens. These screens are the “Lockout Faults”, “Blocking Faults” and “Runtime History”. The default screen is the “Lockout Faults” screen. This screen allows you to view the last ten (10) lockout faults. Preceded by each fault is the date and time of when the fault occurred. - Page 29 Service Manual Service (continued) History Screen The third screen is the “Runtime History”. There are several pieces of information that are displayed on this screen. Items that can be viewed on this screen are as follows: • Power hours – Shows the number of hours the control has been powered on since the last reset. •...
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Page 30: Service Screen
Service Manual Service Service Screen The Service Screen allows the integrated control to override all other heat demands and operate Valve 1 and Valve 2 at high fi re and low fi re conditions. To place the boiler into Service Mode, press the START button. As specifi ed above the integrated control will override all other heat demands, however, all safeties will be active. -
Page 31: Maintenance
Service Manual Maintenance Maintenance and annual startup Table 2A Service and Maintenance Schedules Owner maintenance Service technician (see the Crest User’s Information Manual for (see the following pages for instructions) instructions) General: • Address reported problems, if any • Check boiler area •... -
Page 32: Address Reported Problems
Service Manual Maintenance 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. -
Page 33: Check Expansion Tank
Service Manual Maintenance (continued) Check expansion tank Inspect ignition and flame sense electrodes 1. Expansion tanks provide space for water to move in and out as the heating system water expands due to 1. Remove the ignition and both flame sense electrodes from temperature increase or contracts as the water cools. -
Page 34: Check Flame Signal
Service Manual Maintenance 4. Remove the top access panel(s) to gain access to the Figure 2-2 Burner Assembly gas/air manifold assembly. 5. Remove the gas/air manifold burner access cover NOTE: Be sure to pay close attention to the Lochinvar logo. (FIG. -
Page 35: Cleaning Boiler Heat Exchanger
Service Manual Maintenance (continued) Cleaning boiler heat exchanger Handling ceramic fiber materials REMOVAL OF COMBUSTION CHAMBER LINING 1. Shut down boiler: • Follow the “To Turn Off Gas to Appliance” instructions for the boiler in Section 9 - Startup. The combustion chamber insulation in this WARNING •... - Page 36 Service Manual Maintenance Test low water flow conditions This test is to be carried out once the NOTICE Crest boiler is completely piped in with adequate gas and water flow. Once the test is completed, ensure that the isolation valve is opened up to allow full water flow.
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Page 37: Troubleshooting
Service Manual Troubleshooting Check control module fuses Label all wires prior to disconnection WARNING when servicing controls. Wiring errors can cause improper and ALWAYS check control module fuses before NOTICE dangerous operation. Always replacing control module or any major disconnect power to the boiler components (blower, etc.). -
Page 38: Corrective Action
Service Manual Troubleshooting Table 3A Troubleshooting Chart - No Display FAULT CAUSE CORRECTIVE ACTION - 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. •... -
Page 39: Checking Temperature Sensors
Service Manual 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. - Page 40 Service Manual Troubleshooting Table 3F Troubleshooting Chart - Noisy System FAULT CAUSE CORRECTIVE ACTION - Supply gas problem. Natural and LP gas • Refer to Section 6 - Gas Connections of the Crest pressures should be between 4 inches w.c. Installation and Operation Manual for detailed (1.0 kPa) and 14 inches w.c.
- Page 41 Service Manual Troubleshooting (continued) Table 3G Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION Gas Pressure SW • Measure the supply gas pressure to determine cause Open of failure. Natural and LP gas pressures should be between 4 - 14 inches w.c.
- Page 42 Service Manual Troubleshooting Table 3G (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION • The control board will release the call for heat after a The main control board has received a call set time period.
- Page 43 Service Manual Troubleshooting (continued) Table 3G (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION • Inspect flame rod 1 and associated wiring for damage and connection. Reference page 33 of this manual for removal and cleaning procedures.
- Page 44 Service Manual Troubleshooting Table 3G (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION Gas Valve / Relay • Check wiring harness connection at the gas valve and Failure 1 at the main control board. (will require a manual •...
- Page 45 Service Manual Troubleshooting (continued) Table 3G (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION Transition Gas • Check the wiring harness connection at the gas valve Valve / Relay and the control board. Failure •...
- Page 46 Service Manual Troubleshooting Table 3G (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION • Vent/air intake lengths exceed the maximum allowed lengths. Refer to Section 2 - General Venting of the Fan Speed High Crest Installation...
- Page 47 Service Manual Troubleshooting (continued) Table 3G (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. •...
- Page 48 Service Manual Troubleshooting Table 3G (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION • Check the sensor and its associated wiring. Repair Flue Sensor Shorted or replace the sensor or wiring if damaged. (will require a manual •...
- Page 49 Service Manual Troubleshooting (continued) Table 3G (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. •...
- Page 50 Service Manual Troubleshooting Table 3G (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION • Turn the 120V power OFF. Wait 15 seconds, then turn IO Expander Out the 120V power back ON. Error The control board detected an internal fault.
- Page 51 Service Manual Troubleshooting (continued) Table 3G (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Boiler Interface FAULT DESCRIPTION CORRECTIVE ACTION • Check all connections between the outlet temperature Outlet Sensor sensors and the control board. Make sure all Differential connections are dry and secure.
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Page 52: Combustion Analysis Procedure
Service Manual Troubleshooting Combustion Analysis Procedure Table 3I Flue Products 1. Turn the main power off to the boiler by placing the “On/Off” switch in the OFF position. Natural Gas Flue Products 2. Remove the fitting from the flue collector. Note: Gas Valve CO 2 (%) O 2 (%) -
Page 53: Gas Valve Adjustment Procedure
Service Manual Troubleshooting (continued) Gas valve adjustment procedure Under normal operating conditions this CAUTION valve should not need adjusting. Locate the throttle adjustment screw on the gas valve (see FIG. 3-2). Using a screwdriver, turn the screw a 1/4 turn counterclockwise to increase CO levels or a 1/4 turn clockwise to decrease CO... - Page 54 Troubleshooting NOTES...
- Page 55 Troubleshooting NOTES...
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Page 56: Revision Notes
Revision Notes: Revision A (ECO #C17106) initial release. Revision B (ECO C17419) reflects the addition of the large Crest models (1501 - 2001). FBII-SER Rev B 03/15...
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