Lochinvar 000 Btu/hr, 45 8Troubleshooting, Troubleshooting Guide M9 Solution Boilers, Step

Installation & Service Manual

8Troubleshooting

Troubleshooting Guide: M9 Solution Boilers

Step 1:	Is the spark
	ignitor sparking?
		Yes

Step 2:	Is the pilot
	staying on?

Yes

			Check continuity on the spark				Check for an open
	No		cable. Check for 24 VAC on				sensor. If no open
			the 24v terminal (gray wire)				sensor, make sure
			on the ignition module.				there’s a call for
							heat. If call for heat
							is present, replace
							temperature control.
				No		Yes
		Check the pilot
		tube for gas.
No		Check draft.
					Replace ignition
					module.			No

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

Step 3: Is the gas valve getting 24 VAC

to the MV terminal?

Yes

	Replace the
No
	ignition
	module.

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

Yes

No

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

Yes

No

Check voltage to and from the transformer.

No

Check incoming 120 VAC.

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.

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

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