Lochinvar 402 - 2072 service manual Flow Switch, Flame Sequence, Anti-cycling

Copper-fin II/IIE Boiler and Water Heater Service Manual

3 Troubleshooting (continued)

Table 3E Troubleshooting Chart - Fault Messages Displayed on Operator Interface

FAULT	DESCRIPTION	CORRECTIVE ACTION
	- Either the optional manual reset low gas	• Reset the pressure switches.
	pressure switch or the optional manual reset
	high gas pressure switch tripped.	• Measure the supply gas pressure to determine
Gas Pressure SW		cause of failure. Refer to the Gas Connections
	- Models 992 - 2072 (natural gas) - Automatic	Section of the Installation and Operation Manual for
(Will require a manual	Reset Low Gas is open.	detailed information concerning the gas supply.
reset once the condition
has been corrected.)		• Correct the supply gas pressure if necessary.

Flow Switch/	Either the flow switch or the optional low	• Check pump operation on a call for heat.
	water cutoff is not making.
LWCO		• Check for closed valves or obstructions in the
(Lockout will reset		water piping.
automatically after
5 minutes or may be		• Verify system is full of water and all air has been
reset immediately once		purged from the system.
condition has been
corrected. Press the
RESET button on the
SMART SYSTEM display
to reset.)
Flame Sequence	The flame detector circuit is seeing a flame	• Check supply voltage for proper polarity.
	signal while the gas valve is de-energized.
(Will require a manual		• Check that the gas valve is closed.
reset once the condition
has been corrected. Press		• Check external wiring for voltage feedback.
the RESET button on the
SMART SYSTEM display		• Check the internal wiring for bad connections.
to reset.)
		• Replace main control board.
	The main control board has received a call	• The control board will release the call for heat after
	for heat too quickly after the previous call for	a set time period.
Anti-cycling	heat has ended.	• The control board will release the call for heat if the
		outlet temperature drops too quickly.

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