Knight 285 Service Manual Download

Page: 1 / 44

Service Manual

Models: 80 - 500

This manual must only be
used by a qualified heating
installer / service technician.
Read all instructions,
including this manual and the
Knight Boiler 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.



WARNING

Save this manual for future reference.

Summary of Contents for 285

Page 1: ...technician Read all instructions including this manual and the Knight Boiler 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 WARNING Save this manual for future reference ...

Page 2: ...portant information concerning the life of the product DANGER WARNING CAUTION CAUTION NOTICE DANGER indicates an imminently hazardous situation which if not avoided will result in death or serious injury WARNING indicates a potentially hazardous situation which if not avoided could result in death or serious injury CAUTION indicates a potentially hazardous situation which if not avoided may result...

Page 3: ...in this 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 Crystalline silica inhaled in the form of quartz or cristobalite from occupational sources is carcinogenic to humans Group 1 Avoid breathing dust and contact with skin and eyes Use NIOSH certified du...

Page 4: ...ove 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 in the system may be damaged This can result in substantial property damage Do not use homemade cures or boiler patent medicines Serious damage to the boiler personnel and or property may result Conti...

Page 5: ...nformation Knight boiler 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 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 s...

Page 6: ...g reference is included to specify the Near Boiler Piping specific to the Knight boiler This piping scheme is important for proper operation of the SMART SYSTEM control See the Knight Boiler Installation and Operation Manual for more detailed piping diagrams ...

Page 7: ...1 Service Service Manual 7 1 Service continued The Knight boiler display ...

Page 8: ...1 Service 8 Service Manual 1 Service Control inputs ...

Page 9: ...1 Service Service Manual 9 1 Service continued Control outputs ...

Page 10: ...n can 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 sequences of operation for space heating and DHW operation The combined operation sequence is for a typical application programmed to provide DHW priority Access modes User The user can adjust spa...

Page 11: ...complete and the blocked drain switch and auto reset high limit are closed the control starts the 5 second trial for ignition by sending spark voltage to the spark electrode and opening the gas valve BLR IGNITION OUT 123 9F 129 5 If the control does not detect flame by the end of the trial for ignition the control performs a 10 second postpurge another prepurge and tries to light the burner again ...

Page 12: ...n 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 satisfied BLR SH 41 RATE OUT 123 0F 129 9 Once both calls for heat are satisfied the control will turn off the burner The blower will remain on for the 10 second postpurge cycle Any pumps that are running will continu...

Page 13: ...1 Service Service Manual 13 1 Service continued Display panel menu access Table 2 Use this procedure to access menus from the display panel ...

Page 14: ...1 Service 14 Service Manual 1 Service Display panel parameter access Table 3 This is a typical example of accessing a parameter shown for parameter I2 boiler pump delay ...

Page 15: ...s Yes 4 SH Offset 17 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 No D 1 Reset Last 10 Errors 18 No No Yes Yes 2 Service Mode Delay 18 No No Yes Yes D D A A T T A A F F U U N N C C T T I I O O N N S S E 1 DHW Boiler Set Point 18 Yes Yes Yes Yes 2 S...

Page 16: ...rn Temperature Differential for Ending Anti Cycling 20 No No Yes Yes 3 Ramp Delay On Off 20 No No Yes Yes A A N N T T I I C C Y Y C C L L I I N N G G H 1 SH Controlling Sensor Outlet System Inlet 21 No No Yes Yes 2 SH Source Thermostat BMS and Cascade 21 No No Yes Yes 3 Boiler Cascade Address 21 No No Yes Yes 4 Max Cascade Set Point 21 No No Yes Yes 5 Cascade Offset 22 No No Yes Yes 6 Cascade Diff...

Page 17: ...off with a setting of 32 F The default value is 32 F Night setback times If parameter A6 is set to anything other than 32 F the night setback feature becomes active This will require start and stop times to be programmed for the days that reduced temperatures are required These times can be changed by the user or the installer by accessing parameter A7 Each day of the week Sunday through Saturday ...

Page 18: ...e installer by accessing parameter D2 The time range of this parameter is 0 to 40 minutes The default value is 20 minutes E 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 actual water temperature This parameter can be changed by the installer by accessing parameter E1 Th...

Page 19: ...ntrol will block all SH demands DHW demands will still be active This parameter can be changed by the user or the installer by accessing parameter F5 The temperature range of this parameter is 0 F to 120 F The default value is 80 F Outdoor air shutdown differential The outdoor air shutdown differential parameter is the number of degrees below parameter F5 the outdoor air temperature must go before...

Page 20: ...n 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 parameter is 0 minutes to 40 minutes The default value is 1 minute Inlet temperature differential for ending anti cycling The control will bypass the anti cycling time if the water temperature drops too quickl...

Page 21: ...ether The designated Leader boiler determines the total output 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 requires a unique address see below The default control is Thermostat Boiler cascade address The boiler designated as the Leader needs t...

Page 22: ... this parameter is 0 minutes to 40 minutes The default time is 30 seconds J Service Notification Service notification in months When the boiler control determines that a scheduled service is due based on days of installation the boiler display will alternate the standard boiler display text with the message SERVICE DUE every 5 seconds This parameter is adjustable by the installer by accessing para...

Page 23: ...0 in the Knight Installation 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 above return water temperature If combustion or performance indicate need Clean heat exchanger Remove and clean burner using compressed air only Clean the blower wheel ANNUAL START UP Owner maintenance see t...

Page 24: ...ir vicinity they must be removed If they cannot be removed reinstall the air and vent lines per this manual and the Knight Boiler Installation and Operation Manual Inspect boiler interior 1 Remove the front access cover and inspect the interior of the boiler 2 Vacuum any sediment from inside the boiler and components Remove any obstructions Clean condensate trap 1 Inspect the condensate drain line...

Page 25: ...Knight Boiler 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 inspection agency to ensure that the product has not been affected by corrosive water conditions and to ensure that the valve and discharge line have not been altered or tampered with illegally Certain ...

Page 26: ...y 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 Sectio...

Page 27: ... 3 Remove the blower assembly gas air arm from the heat exchanger access cover Set bolts aside 4 Remove the nuts securing the heat exchanger access cover to the heat exchanger and set aside 5 Remove the heat exchanger access cover cover gasket s and chamber insulation assembly The boiler contains ceramic fiber materials Use care when handling these materials per instructions on page 3 of this manu...

Page 28: ...c natural 13 inches w c LP with no flow lockup or with boiler on Minimum 4 inches w c natural 8 inches w c LP with gas flowing verify during boiler startup Check control module fuses ALWAYS check control module fuses before replacing control module or any major components blower etc If one of these fuses is blown it can prevent the control module or other components from operating 1 Turn OFF the p...

Page 29: ...ew temperature setting Remote 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 resistance of outdoor air sensor and compare to Table 7C on page 30 of this manual Unit locked out on fault Consult display for specific fault Refer to fault descriptions on page 32 o...

Page 30: ...able 7C 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 15 311 0 85 362 70 11 883 10 62 465 80 9 299 Checking temperature sensors The boiler temperature sensors inlet water outlet water system water flue and outdoor air are all resistance type devices The fol...

Page 31: ...and inspection procedure Clean or replace the burner as necessary Low water flow through the heat exchanger Refer to Section 6 Hydronic Piping of the Knight 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 Air in the piping system Properly purge all air f...

Page 32: ...oiler piping Verify system is 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 this manual Blocked Drain SW will require a manual reset once condition has been corrected Press the RESET button on the SMART SYSTEM display to reset The blocked drain swi...

Page 33: ...ht Boiler Installation 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 pipes are correctly installed and that 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 igni...

Page 34: ...and is not damaged Verify 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 ignition attempt If no voltage is present replace the main control board If 24 vac is present at the main control board check the wiring between the main control board and the gas va...

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 something other than an outlet sensor check temperature setting of the main control board If the optional manual reset high limit has tripped check setting of the device Check resistance of water sensors and compare to Tab...

Page 36: ...RESET button on the SMART SYSTEM display to reset Either the inlet water or outlet water temperature sensor has been disconnected Check the sensors and their associated wiring 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 Shorted will require a manual ...

Page 37: ...ing of the Knight Boiler Installation and Operation Manual for the proper piping methods for the Knight boiler Check for 120 vac to the boiler pump motor on a call for heat If voltage is not present check the wiring back to the main control board Replace the main control board if necessary If 120 vac is present on a call for heat and the boiler pump is not operating replace the pump Verify that th...

Page 38: ...is set to the proper speed or that the boiler pump is the proper size Reference Section 6 Hydronic Piping of the Knight Boiler Installation and Operation Manual for boiler pump specifications Replace the main control board 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 Replace the control Paramet...

Page 39: ... main control board Replace the main control board if necessary 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 size Reference Section 6 Hydronic Piping of the Knight Boiler Installation and Operation Manual for boiler pump specifications Low 24 vac 120 vac in...

Page 40: ...actions Table 10 Troubleshooting Chart Combustion Levels P PO OS SS SI IB BL LE E C CA AU US SE E C CO OR RR RE EC CT TI IV VE E A AC CT TI IO ON N Vent Air Intake Length or Obstruction Refer to Section 3 General Venting of the Knight Boiler Installation and Operation Manual for the proper venting and air intake methods for the Knight boiler Check for obstructions at the vent air intake terminals ...

Page 41: ...ble causes in Table 10 on page 40 or replace the gas valve Figure 6 Gas Valve Adjustment Models 80 285 There is no adjustment for the gas valve on the 399 model Revisit the possible causes in Table 10 on page 40 or replace the gas valve Model 500 Locate the throttle adjustment screw on top of the gas valve see FIG 7 Using a screwdriver turn the screw a 1 4 turn clockwise to increase CO2 levels or ...

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

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

Page 44: ...KB SER 03 CP 3M 3 07 ...

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