Lochinvar 3, 2 Troubleshooting continued, Fault, Cause, Corrective Action, No Display, No Burner

								Service Manual
3 Troubleshooting (continued)
Table 3A Troubleshooting Chart - No Display
FAULT	CAUSE			CORRECTIVE ACTION
	- No 120 vac supplied to unit.	•	Check external line switch, fuse, or breaker.
		•	Check position of ON/OFF switch. Turn switch to the
			ON position.
		• Check 120 vac through the ON/OFF switch.
		• Check wiring				harness connection				between	display
			board		and	main	control		board. Connect
No Display			harness at both points.
	- No voltage through the switch.	•	Replace switch.
	- Bad display board.	•	Replace board.
	- Bad main control board.	•	Replace the main control board.
	- Blown fuse.	• Replace			fuse	F2 on	the main control board, see
			page 38 of this manual.
	- Main control board temperature set point	•	Review temperature setting.
	satisfied.
	- Remote thermostat satisfied.	•	Review remote thermostat setting.
No Burner
	- Outside air temperature above Warm	•	Check		location of		outside	air	sensor.		Check
Operation
	Weather Shutdown (WWSD) set point for		resistance of outdoor air sensor and compare to Table
	main control board.		3C on page 38 of this manual.
	- Unit locked out on fault.	•	Consult		display for		specific	fault.		Refer	to fault
			descriptions on page 40 of this manual for corrective
			actions.
	- Ramp delay active.	•	Check ramp delay parameter settings. Optional PC
			software required.
Unit Does Not
		•	Turn ramp delay feature off.					See page 20 of this
Modulate
Up to 100%			manual for instructions on how to turn this feature off.
	- Boiler controlled by BMS.	•	Check BMS parameter settings.

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