Lochinvar WBN050 Service Manual

WB-SER Rev D

Service Manual

Models: 50 - 210

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

Contents

CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 2	2. MAINTENANCE
Hazard Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	2	Maintenance and Annual Startup . . . . . . . . . . .	. . . . . . .	23-27
PLEASE READ BEFORE PROCEEDING . . . . . . . . . . . .	3	3. TROUBLESHOOTING
Handling Ceramic Fiber Materials . . . . . . . . . . . . . . . . . . .	3	Before Troubleshooting . . . . . . . . . . . . . . . . . . .	. . . . . . .	28
When servicing boiler . . . . . . . . . . . . . . . . . . . . . . . . . .	4	Check Control Module Fuses . . . . . . . . . . . . . .	. . . . . . .	28
Boiler operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	4	Table 3A - Troubleshooting Chart - No Display .	. . . . . . .	29
Boiler water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	4	Checking Temperature Sensors . . . . . . . . . . . .	. . . . . . .	30
Freeze protection fluids . . . . . . . . . . . . . . . . . . . . . . . .	4	Table 3E - Troubleshooting Chart - Noisy System . . . . . 31
WHAT IS IN THIS MANUAL . . . . . . . . . . . . . . . . . . . . . . .	5	Table 3F - Troubleshooting Chart - Fault Messages . . . .		32-39
1. SERVICE		Combustion Analysis Procedure . . . . . . . . . . . .	. . . . . . .	40
Near Boiler Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	6	Table 3G - Troubleshooting Chart - Combustion Levels		40
The Knight Wall Mount Display . . . . . . . . . . . . . . . . . . . . .	7	Table 3H - Flue Products . . . . . . . . . . . . . . . . . .	. . . . . . .	40
Control Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8	Gas Valve Adjustment Procedure . . . . . . . . . . .	. . . . . . .	41
Control Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	9	Revision Notes . . . . . . . . . . . . . . . . . . . . . . . . .	Back Cover
General Operation . . . . . . . . . . . . . . . . . . . . . . . . . . .	10
Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . .	11-12
Display Panel Menu Access . . . . . . . . . . . . . . . . . . . . . .	13
Display Panel Parameter Access . . . . . . . . . . . . . . . . . .	14
Parameter Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	15-16
Viewable and Changeable Control Parameters . . . . . . .	17-22

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 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 in minor or moderate injury.

CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not avoided, may result in property damage.

NOTICE indicates special instructions on installation, operation, or maintenance that are important but not related to personal injury or property damage.

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Service Manual

Please read before proceeding

WARNING	Installer	–	Read	all	instructions,	NOTICE	When calling or writing about the boiler –
	including this manual and the Knight						Please have the boiler model and serial
	Wall Mount Installation and Operation						number from the boiler rating plate.
	Manual, before installing. Perform steps						Consider piping and installation when
	in the order given.
							determining boiler location (see the Knight
	User – This manual is for use only by a						Wall Mount Installation and Operation
	qualified	heating		installer/service			Manual).
	technician.	Refer to		the	Knight Wall		Any claims for damage or shortage in
	Mount User’s		Information		Manual for
							shipment must be filed immediately against
	your reference.
							the transportation company by the
	Have this boiler serviced/inspected by a						consignee.
	qualified service technician at least
	annually.

Failure to comply with the above could result in severe personal injury, death or substantial property damage.

Handling ceramic fiber materials

REMOVAL OF COMBUSTION CHAMBER LINING

WARNING The combustion chamber insulation in this appliance 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 in the form of quartz or cristobalite from occupational sources is carcinogenic to humans (Group 1).” Normal operating temperatures in this appliance are below the level to convert ceramic fibers to cristobalite. Abnormal operating conditions would have to be created to convert the ceramic fibers in this appliance to cristobalite.

The ceramic fiber material used in this appliance is an irritant; when handling or replacing the ceramic materials it is advisable that the installer follow these safety guidelines.

Avoid breathing dust and contact with skin and eyes.

•Use NIOSH certified dust respirator (N95). This type of respirator is based on the OSHA requirements for cristobalite at the time this document was written. Other types of respirators may be needed depending on the job site conditions. Current NIOSH recommendations can be found on the NIOSH website at http://www.cdc.gov/niosh/homepage.html. NIOSH approved respirators, manufacturers, and phone numbers are also listed on this website.

•Wear long-sleeved, loose fitting clothing, gloves, and eye protection.

Apply enough water to the combustion chamber lining to prevent airborne dust.

Remove the combustion chamber lining from the appliance and place it in a plastic bag for disposal.

Wash potentially contaminated clothes separately from other clothing. Rinse clothes washer thoroughly.

NIOSH stated First Aid.

Eye: Irrigate immediately.

Breathing: Fresh air.

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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.

•Should overheating occur or gas supply fail to shut off, do not turn off or disconnect electrical supply to circulator. 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.

Boiler water –

•Thoroughly flush the system (without boiler connected) to remove 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.

•Continual fresh make-up water will reduce boiler life. Mineral buildup in the heat exchanger reduces heat transfer, overheats the stainless steel heat exchanger, and causes failure. Addition of oxygen carried in by makeup water can cause internal corrosion. Leaks in boiler piping must be repaired at once to prevent the introduction of makeup water.

Freeze protection fluids –

•NEVER use automotive antifreeze. Use only inhibited propylene glycol solutions which are specifically formulated for hydronic systems. Ethylene glycol is toxic and can attack gaskets and seals used in hydronic systems.

4

What is in this manual?

Service

Near boiler piping

• Typical system components

The Knight wall mount boiler 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 operates

•Access modes -- user and installer

•Sequence of operation -- Domestic Hot Water (DHW)/space heating

Control panel menu access

•Accessing programming mode and locating menus (See separate guide covering the PC interface.)

Control panel parameter access

• Accessing and changing parameters from the display panel

Quick start information -- parameter table

•An index of available adjustments and readouts, where to access them and where to find detailed information.

Knight wall mount 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

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

•Check water system

•Check expansion tank

•Check boiler relief valve

•Inspect ignition electrode

•Check ignition ground wiring

•Check all boiler wiring

•Check control settings

•Perform start-up and checks

•Check burner flame

•Check flame signal

•Check flue gas temperature

•General maintenance

•Review with owner

•Cleaning boiler heat exchanger

•Oiled bearing circulators

Troubleshooting

•Troubleshooting table - No display

•Checking temperature sensors

•Sensor tables

•Troubleshooting table - Fault messages displayed on boiler interface

•Combustion analysis procedure

•Gas valve adjustment procedure

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Service Manual

1Service

Near boiler piping

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

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Service Manual

1Service (continued)

The Knight wall mount display

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1Service

Control inputs

GAS PRESSURE SWITCH

DHW THERMOSTAT

ROOM THERMOSTAT /

ZONE CONTROL

FLOW SWITCH

SYSTEM SENSOR

OUTDOOR SENSOR

SEQUENCER / BUILDING

MANAGMENT SYSTEM

LOW WATER CUTOFF

INLET TEMPERATURE

SENSOR

OUTLET TEMPERATURE /

HIGH LIMIT SENSOR

FLUE GAS SENSOR

AIR PRESSURE SWITCH

FLAME SENSOR

BLOCKED DRAIN SWITCH

DISPLAY PANEL

PC INTERFACE

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Service Manual

LOW VOLTAGE

CONNECTION

BOARD

SMART CONTROL

MODULE

Service Manual

1Service (continued)

Control outputs

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Service Manual

1Service

General Operation

How the boiler operates

The Knight wall mount boiler 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 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.

How the control module operates

The Knight wall mount control module receives input from boiler sensors. The control module activates and controls the blower and gas valve to regulate heat input and switches boiler, DHW and system pumps on and off as needed. The user/installer programs the module to meet system needs by adjusting control parameters. These parameters set operating temperatures and boiler operating modes. Boiler operation 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.

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Access modes

User

The user can adjust space heating set point using the UP and DOWN buttons at any time during normal operation. By entering the USER code (0704), the user can also change temperature units, time and date, and night setback settings. In user mode, the following parameters can be viewed but not changed: Boiler outlet water temperature in DHW mode; boiler model number; software version; total operating hours, and total cycles.

Installer

Most parameters are available only to the installer, accessible only by entering the installer access code (5309).

Saving parameters

To save parameters:

Press the ENTER/RESET button.

To keep parameter settings only for a current operating cycle:

Press the MENU/EXIT button 1 time to return to the parameter listings; press again to return to the menu listings.

Service Manual

1Service (continued)

Sequence of operation

Table 1A Sequence of operation - space heating and DHW

OPERATION	DISPLAY
1. Upon a call for heat, the control turns on the appropriate pumps	BLR: Standby
(system and boiler pumps for space heating call; DHW pump	OUT: 123.8F(129)
for DHW call).
2. The control connects 120 vac to the blower. The blower does
not run at this time.
• If the unit is equipped with a flow switch or low water cutoff, it
must close before the control powers up the blower.
• If the unit is equipped with a manual reset high limit it must be	BLR: Standby
closed before the control powers up the blower.
• If the unit is equipped with a solenoid valve and/or a vent
valve, they will be energized along with the blower.	OUT: 123.8F(129)
• If the unit is equipped with a gas pressure switch, it must close
at this time.
• If there is an auxiliary device connected to the unit, the unit
will then provide 24 vac to its enable relay. If the auxiliary
device has a proving switch, it must close before the
sequence continues.
3. The control then starts a 10 second prepurge cycle.	BLR: PREPURGE
	OUT: 123.9F(129)
4. Once the prepurge cycle is complete, and the blocked drain	BLR: IGNITION
switch and auto-reset high limit are closed, the control starts
the 5 second trial for ignition by sending spark voltage to the	OUT: 123.9F(129)
spark electrode and opening the gas valve.
5. If the control does not detect flame by the end of the trial for	BLR: POSTPURGE, PREPURGE
ignition, the control performs a 10 second postpurge, another
prepurge and tries to light the burner again. If the burner does	OUT: 123.9F(129)
not light after 4 trials, the control locks out for 1 hour and then
tries another set of 4 trials.
6. If the control detects a flame before the trial for ignition ends, it	BLR: SH 20% RATE
begins to modulate the burner in order to maintain the set point.
If the boiler lights due to a space heating call for heat, and the
ramp delay function is active (default is off), the modulation	OUT: 124.8F(129)
will be held to a series of increasing limits after the burner has
lit.
7. If the space heating call for heat is active, and the DHW	BLR: DHW 85% RATE
thermostat closes, the control will turn on the DHW pump, wait
2 seconds, and then turn off the boiler pump. This will divert
the hot water away from the heating zone(s) and send it to the	OUT: 177.8(180)
DHW tank instead. The control will then modulate to maintain
the outlet temperature to the DHW boiler set point.
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Service Manual

1Service

Sequence of operation (continued)

Table 1A (continued from previous page) Sequence of operation - space heating and DHW

	OPERATION	DISPLAY
8. If the DHW thermostat remains on for more than 30 minutes,
	and the space heating call for heat is also on, then the control	BLR: SH 41% RATE
	will turn on the boiler pump, turn off the DHW pump after 2
	seconds, and resume modulating based on the space heating
	set point. As long as both the space heating and DHW calls for	OUT: 123.0F(129)
	heat remain active, the control will switch back and forth
	between the two modes until one of them is satisfied.
9. Once both calls for heat are satisfied, the control will turn off the		BLR: POSTPURGE
	burner. The blower will remain on for the 10 second postpurge
	cycle. Any pumps that are running will continue to run for their	OUT: 127.4F(129)
	respective pump delay times, then turn off.
10.	Boiler pump off, system pump continues its delay if longer.	BLR: Standby
		OUT: 124.7F(129)
11.	System pump off.	BLR: Standby
		OUT: 122.9F(129)

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Service Manual

1Service (continued)

Display panel menu access

Table 1B Use this procedure to access menus from the display panel

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Service Manual

1Service

Display panel parameter access

Table 1C This is a typical example of accessing a parameter, shown for parameter I2, boiler pump delay

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