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HVACmech
Oct 2, 2013, 05:36 PM
I have an intercity gas forced air furnace. IT has a Honeywell spark ignition control module. The pilot light lites, but the main burners will not come on. The flame sensing rod is clean and appears to be in the flame. I am getting 24 volts to the gas valve. I suspect the gas valve or could it be in the module? I figure that if I am getting spark and pilot light and 24 volts at the gas valve, then it is the valve? What do you think?

Grady White
Oct 3, 2013, 07:19 PM
If you are getting 24v to the gas valve & no main burner, most likely the gas valve is at fault. Silly question I know but I have to ask: Is the switch on the valve turned on?

HVACmech
Oct 4, 2013, 04:41 PM
If you are getting 24v to the gas valve & no main burner, most likely the gas valve is at fault. Silly question I know but I have to ask: Is the switch on the valve turned on?

Thanks for the input. Yes, the switch on the gas valve is in the on position(one of the first things I checked) but thanks for asking. Not a silly question. I did furnace work for 6 years, but has been 5 since I have done any and am helping a friend. He had someone come look at his furnace and they are trying to rip him off by charging an outrageous amount. Thanks

Grady White
Oct 4, 2013, 05:54 PM
Since that furnace is a spark to pilot ignition system, the gas valve should have 3 terminals. They would likely be marked MV (main valve), PV (pilot valve) & MV/PV (common).

Are you getting 24v between MV & MV/PV? If you are not & the spark does not stop, the system is not sensing the pilot flame.

HVACmech
Oct 7, 2013, 06:09 PM
Since that furnace is a spark to pilot ignition system, the gas valve should have 3 terminals. They would likely be marked MV (main valve), PV (pilot valve) & MV/PV (common).

Are you getting 24v between MV & MV/PV? If you are not & the spark does not stop, the system is not sensing the pilot flame.

I am sure that I was getting 24v between MV & MV/PV but will double check to make sure. The pilot did light( there was flame) however the spark did not stop. I'll check the sensing rod to make sure it is the flame where it needs to be. Thanks.