Lochinvar 399 - 800 Service Blk, Low 24 VAC, Watch Dog Error, Write EEProm, CRC Parameters

FAULT

DESCRIPTION

CORRECTIVE ACTION

While the unit is in Service Mode, the outlet

• Establish a heating load to remove the heat from the

temperature has exceeded 185°F.

boiler loop.

• Verify that the system is full of water and that all air

has been properly purged from the system.

• Verify that the boiler is piped properly into the heating

system. Refer to Section 6 - Hydronic Piping of the

Knight XL Installation and Operation Manual for the

proper piping methods for the Knight

XL boiler.

Service Blk

• Check voltage to the boiler pump motor on a call for

heat. If voltage is not present, check the wiring back

to the pump relay. Replace the pump relay 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

XL Installation and Operation Manual for boiler

pump specifications.

120 VAC input to the main control board has

• Check 120 VAC supply to the transformer.

dropped below 80 VAC.

Low 24 VAC

• Check wiring connections at the low voltage terminal

strip.

• Check the wire size/length to remote devices.

• Replace the transformer.

Watch Dog Error

The main control board has detected an

• Replace the main control board.

internal fault.

Write EEProm

The main control board has detected an

• Replace the main control board.

internal fault.

The main control board has detected an

• Replace the main control board.

CRC Parameters

internal fault.

The main control board has detected an

• Press the ENTER/RESET button on the SMART

No Error Stored

internal fault.

SYSTEM display panel.

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