I have a GMVC95 furnace that went out with a E6 code - (Low Pressure Switch contacts closed or short in wires). Low fire would ignite but went out after a short time. Troubleshooting revealed no short in wires and switch operated but with very little suction applied. I thought 'weak spring?' and found what looked like a square adjustment screw on the back of pressure switch. Test of 1/4 turn counterclockwise - no change. Test of 1/4 turn clockwise resulted in furnace operating normal - 3 days now. I think this adjustment tightened up the spring so the switch would not close too soon but I do not know if the adjustment is correct or safe to leave the house for a week. Do I leave it as is, pay a HVAC company to check it or go ahead and replace it with a new unit from Goodman?
dcf725
That is DANGEROUS as you have thrown the factory calibration of the switch out and it is unsafe. Need a new switch ASAP.
That screw had glue in it to prevent tampering and for legal reasons.
A tech would check the draft on it with a manometer to see if the switch was the problem. You may have an obstruction with the venting or the condensate is not draining properly. The switches are cheap and do fail so you may want to try it yourself. If it still acts up get a tech to check the draft.
That screw had glue in it to prevent tampering and for legal reasons.
A tech would check the draft on it with a manometer to see if the switch was the problem. You may have an obstruction with the venting or the condensate is not draining properly. The switches are cheap and do fail so you may want to try it yourself. If it still acts up get a tech to check the draft.
Thanks, Yuri. You confirmed my suspicion and original thought and I will proceed accordingly. First of all, I would not have even tried anything like that but it was a weekend evening during the worst winter storm we've had. Secondly, I know about lockouts to prevent tampering and I can assure you there was no glue on the threads as I gently tried to turn the screw - no resistance. THANKS AGAIN!
Get a new switch. And also check the hoses for moisture. Do both the vent and intake terminate in the same area, or is one at another location.
Thanks, beenthere. Just signed up on DIY and made post before activation - had to update location.
No moisture in vac hose and it also attaches to the top side of the IDM housing. Intake is in basement and vent is outside under eave. Both clear. I will have to buy both the low fire and high fire pressure switches as an assembly because that's all I can find at Goodman for this model.
No moisture in vac hose and it also attaches to the top side of the IDM housing. Intake is in basement and vent is outside under eave. Both clear. I will have to buy both the low fire and high fire pressure switches as an assembly because that's all I can find at Goodman for this model.
When the intake is in one area, and the exhaust in another. Wind can cause the pressure switch to close when the inducer is not running.
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