Lochinvar 500 Troubleshooting Guide, 90,000 - 270,000 Btu/hr Models - Water Heaters F1, Step Step

Installation & Service Manual

9Troubleshooting

Troubleshooting Guide:

90,000 - 270,000 Btu/hr Models - Water Heaters F1

Step 1:	Is the pilot lit?
			No	Check gas pressure.
				Check the pilot assembly
				and thermocouple. Clean
				the thermocouple and
		Yes
				pilot or replace.

Check for an open sensor. If no open sensor, make sure there’s a call for heat. If call for heat is present, replace temperature control

Step 2:

Step 3:

62

Is the gas valve getting 24VAC to the MV terminal?

Yes

Check gas pressure and make sure the gas valve knob is on

No

Check voltage to and from the transformer.

No

Check incoming 120 VAC

No	Is there 24 VAC (purple
	wire) on the 4-pin
	connector plug on the
	temperature controller?
		Yes

No

Check 24 VAC at R and W on the terminal strip.

Yes

Check each of the following for an open: -white and purple wire on the LWCO plug -rollout switch -manual reset high limit -spill switch

If any of these devices are open, press the reset button.

No

Is there 24 VAC (tan wire) on the 4-pin connector plug on the temperature controller?

Yes

Check each of the following for an open:

-X and B on the terminal strip -purple and gray wires on the vent damper plug

-V and P on the terminal strip -auto reset high limit