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Maintenance

26

Service Manual

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. Inspect boiler ground wire from the heat exchanger access

cover to ground terminal strip.

2. Verify all wiring is in good condition and securely

attached.

3. Check ground continuity of wiring using continuity

meter.

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.  See Section 1 of
this manual.  Adjust settings if necessary.  See Section 1 of
this manual for adjustment procedures.

2. Check settings of external limit controls (if any) and

adjust if necessary.

Perform start-up and checks

1.

Start boiler and perform checks and tests specified in
Section 10 - Start-up of the Knight XL Installation and
Operation Manual.

2.

Verify cold fill pressure is correct and that operating
pressure does not go too high.

Check burner flame

1.

Inspect flame through observation window.

2.

If the flame is unsatisfactory at either high fire or low fire,
turn off boiler and allow boiler to cool down.  Remove
the burner and clean it thoroughly using a vacuum
cleaner or compressed air.  Do not use compressed air to
clean burner if performed inside a building.

3.

Remove the burner, reference FIG.’s 2-2 thru 2-4.

4.

When replacing the burner, ensure gasket is in good
condition and positioned correctly (FIG.’s  2-2 thru 2-4).

AIR / GAS ARM

SCREWS

(QTY. 5)

GASKET

BURNER

Figure 2-2 

Burner Assembly - Model 399

BURNER

GASKET

SCREWS

(QTY. 5)

AIR / GAS ARM

Figure 2-3 

Burner Assembly - Model 500

Summary of Contents for KNIGHT 399 - 800

Page 1: ...ician 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 person...

Page 2: ...t but not related to personal injury or property damage CONTENTS 2 Hazard Definitions 2 PLEASE READ BEFORE PROCEEDING 3 Handling Ceramic Fiber Materials 3 When servicing boiler 4 Boiler operation 4 Bo...

Page 3: ...product contains ceramic fiber material Ceramic fibers can be converted to cristobalite in very high temperature applications The International Agency for Research on Cancer IARC has concluded Crysta...

Page 4: ...ve sediment The high efficiency heat exchanger can be damaged by build up or corrosion due to sediment Do not use petroleum based cleaning or sealing compounds in the boiler system Gaskets and seals i...

Page 5: ...Knight XL operation A General B Temperature Setting C Data Logging D Functions E DHW Settings F Outdoor Air Reset Curve G Anti cycling H Control Modes I Circulation Pumps J Service Notification Mainte...

Page 6: ...P DOMESTIC HOT WATER PUMP SYSTEM PUMP 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 operat...

Page 7: ...display during normal operation to show outlet and return temperatures fan speed and flame signal Press to toggle between digits when entering access code or between hour minutes etc when entering dat...

Page 8: ...OOR SENSOR OPTIONAL SEQUENCER BUILDING MANAGEMENT SYSTEM OPTIONAL LOW VOLTAGE CONNECTION BOARD INLET TEMPERATURE SENSOR OUTLET TEMPERATURE SENSOR FLUE GAS SENSOR HIGH LIMIT FLAME SENSOR LOW WATER CUTO...

Page 9: ...tinued LOW VOLTAGE CONNECTION BOARD SMART CONTROL MODULE ALARM BELL AUX DEVICE RELAY RUN TIME CONTACTS SEQUENCER BUILDING MANAGEMENT SYSTEM BOILER PUMP SYSTEM PUMP DHW PUMP IGNITOR BLOWER GAS VALVE DI...

Page 10: ...be based on boiler outlet water temperature boiler return water temperature or system supply temperature depending on the parameter setting Sequence of operation Table 1 shows control module normal s...

Page 11: ...ntrol does not detect flame before the trial for ignition ends the control will perform a 10 second postpurge The 399 model will start another prepurge and trial for ignition If the burner does not li...

Page 12: ...g based on the space heating set point As long as both the space heating and DHW calls for heat remain active the control will switch back and forth between the two modes until one of them is satisfie...

Page 13: ...ENU EXIT UP PREVIOUS UP PREVIOUS UP ENTER RES DOWN DOWN DOWN DOWN DOWN To select a highlighted menu press the ENTER RESET button one time The display will change to the first parameter under that menu...

Page 14: ...to return to normal operation OUT 123 7 F A General B Temp Settings I2 Postrun Time SH Pump 0 67 minutes I2 Postrun Time SH Pump 0 50 minutes I2 Postrun Time SH Pump I1 Postrun Time System Pump I Circ...

Page 15: ...7 No No Yes Yes 5 SH Differential 18 No No Yes Yes C 1 Hours Running SH 18 Yes No Yes No 2 Hours Running DHW 18 Yes No Yes No 3 Ignition Attempts 18 Yes No Yes No 4 Show Last 10 Errors 18 Yes No Yes N...

Page 16: ...turn Temperature Differential for Ending Anti Cycling 20 No No Yes Yes 3 Ramp Delay On Off 20 No No Yes Yes ANTI CYCLING H 1 SH Controlling Sensor Outlet System Inlet 21 No No Yes Yes 2 SH Source Ther...

Page 17: ...value is 125 F 52 C SH minimum set point The SH minimum set point sets the minimum water temperature set point that can be used for space heating operation The user or installer will not be able to p...

Page 18: ...W 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 actual water temperature This parameter...

Page 19: ...t FIG 1 1 This parameter can be changed by the installer by accessing parameter F4 The temperature range of this parameter is 0 F 18 C to 190 F 88 C The default value is 70 F 21 C Outdoor air shutdown...

Page 20: ...shown in the display until the time has elapsed or the water temperature drops below parameter G2 This parameter can be changed by the installer by accessing parameter G1 The time range for this param...

Page 21: ...needed from the group based on the set point and controlling sensor reading It assigns portions of this output to itself Leader and the Member boilers When Cascade is selected each boiler in the group...

Page 22: ...er is adjustable by the installer by accessing parameter I3 The time range for this parameter is 0 minutes to 40 minutes The default time is 30 seconds J Service Notification Service notification in m...

Page 23: ...lation and Operation Manual Flame inspection stable uniform Flame signal at least 10 microamps at high fire Clean the heat exchanger if flue temperature is more than 54 F 30 C above return water tempe...

Page 24: ...l the air and vent lines per this manual and the Knight XL Installation and Operation Manual Inspect boiler interior 1 Remove the front access cover and inspect the interior of the boiler 2 Vacuum any...

Page 25: ...the Knight XL Installation and Operation Manual before proceeding further Safety relief valves should be re inspected AT LEAST ONCE EVERY THREE YEARS by a licensed plumbing contractor or authorized in...

Page 26: ...display to Parameter Mode and check all settings See Section 1 of this manual Adjust settings if necessary See Section 1 of this manual for adjustment procedures 2 Check settings of external limit con...

Page 27: ...revention fluid in system do not drain 2 Allow time for the boiler to cool to room temperature if it has been firing 3 Remove the blower assembly gas air arm from the heat exchanger access cover Set b...

Page 28: ...Minimum 4 inches w c 1 0 kPa natural 8 inches w c 2 0 kPa LP with gas flowing verify during boiler startup Check control module fuses ALWAYS check control module fuses before replacing control module...

Page 29: ...ote thermostat satisfied Review remote thermostat setting Outside air temperature above Warm Weather Shutdown WWSD set point for main control board Check location of outside air sensor Check resistanc...

Page 30: ...ble 3D Outdoor Air Sensor Resistance vs Temperature Temperature Resistance Temperature Resistance 50 490 813 20 46 218 40 336 606 30 34 558 30 234 196 40 26 099 20 165 180 50 19 900 10 118 018 60 15 3...

Page 31: ...on procedure Clean or replace the burner as necessary Low water flow through the heat exchanger Refer to Section 6 Hydronic Piping of the Knight XL Installation and Operation Manual for minimum flow r...

Page 32: ...full of water and all air has been purged from the system Check for loose or misplaced jumpers if flow switch or LWCO is not installed Blown fuse Replace fuse F2 on the control board see page 28 of t...

Page 33: ...and Operation Manual for detailed information concerning the gas supply Verify that the plastic hose from the gas valve to the air inlet is connected and is not damaged Verify that the vent air intake...

Page 34: ...erify that the vent air intake pipes are installed correctly and there are no obstructions Check for 24 VAC to the gas valve at the 2 pin connection on the side of the main control board during the ig...

Page 35: ...at and the boiler pump is not operating replace the pump If the system pump is a variable speed pump ensure that the system flow is not less than the boiler flow If operating on either an inlet or sys...

Page 36: ...Repair or replace the sensor or wiring if damaged Measure the resistance of the sensors and compare the resistance to the tables on page 30 of this manual Replace the sensor if necessary Sensor Shorte...

Page 37: ...t XL Installation and Operation Manual for the proper piping methods for the Knight XL boiler Check for voltage to the boiler pump motor on a call for heat If voltage is not present check the wiring b...

Page 38: ...eset After downloading parameters from a laptop the main control board must be reset Press the ENTER RESET button on the SMART SYSTEM display panel APS Open will require a manual reset once the condit...

Page 39: ...ecessary If 120 VAC is present on a call for heat and the boiler pump is not operating replace the pump Verify that the boiler pump is set to the proper speed or that the boiler pump is the proper siz...

Page 40: ...and corrective actions Table 3G Troubleshooting Chart Combustion Levels POSSIBLE CAUSE CORRECTIVE ACTION Vent Air Intake Length or Obstruction Refer to Section 3 General Venting of the Knight XL Insta...

Page 41: ...urn counterclockwise to increase CO2 levels or a 1 4 turn clockwise to decrease CO2 levels After one adjustment on the valve follow the Combustion Analysis Procedure on page 40 of this manual to measu...

Page 42: ...4 Notes 42 Service Manual...

Page 43: ...4 Notes Service Manual 43...

Page 44: ...reflects the addition of references to periodic cleaning of screens in vent terminations and safety shutoff testing and instructions Revision D ECO C02738 reflects the addition of the Gas Valve Adjust...

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