Lochinvar 50-210 Troubleshooting continued, Fault, Cause, Corrective Action, Service Manual

Service Manual

3Troubleshooting (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
			harness at both points.
No Display
	- 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 F3 on the main control board, see
			page 28 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.		3D on page 30 of this manual.
	- Unit locked out on fault.	•	Consult display for specific fault.					Refer	to fault
			descriptions on page 32 of this manual for corrective
			actions.
	- Ramp delay active.	•	Check ramp delay parameter settings. Optional PC
			software required.
		•	Turn ramp delay feature off.				See page 20 of this
			manual for instructions on how to turn this feature off.
Unit Does Not
	- Boiler controlled by BMS.	• Check BMS parameter settings. Optional PC
Modulate			software required.
Above 50%
	- Flue sensor open.	•	Verify that the flue sensor is located in the flue outlet.
		•	Check wiring connections at the flue sensor.
		•	Check the resistance of the flue sensor and compare
			to Table 3C on page 30 of this manual.
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