Nordyne Model# M1GC0070A BW

[Mastertech]

Hi Folks!

Here is the issue I am having with this unit.

I can light the pilot and it stays light no problem, turn the thermostat up and the you can hear the gas valve click and the burner lights. After about a minute, to a minute and a half, the burner and the pilot goes out. The furnace is set up for propane so I had the propane company come out and check everything on their end. They found a bad regulator so they replaced that and adjusted the gas pressure so it's within spec's....still same problem. Gas guy said probably a bad gas valve on the furnace so I ordered a new one and installed it, same problem but not as frequent now, probably just a coincidence. I don't mind that I replaced the gas valve as the solenoid housing was cracked(large crack) around the windings anyway, but it didn't solve my issue. Got up on the roof and checked the roof jack.....corrected a minor issue there...no change in the symptoms. I have checked voltages with a fluke 88 voltmeter and have 27.3 volts to the gas valve. I have noticed that when the furnace actually works it heats the house up great....BUT...it seems as if the fan takes much longer to kick on than it used to even though I have a nice strong flame coming out of the burner.
Is it possible/likely the fan switch is bad and the blower is not kicking on soon enough so the system is shutting down rather than over heating?

[Robert]

Test gas valve terminals and see if you lose the 27.3vac when the burner and pilot goes out or does the low voltage remain at gas valve ?


Thanks,
Robert