Goodman 80% Furnace Won't Start With Side Cover On

rlelliott

I have a 1yr old Goodman 80% furnace that doesn't want to ingnite when the side cover is properly installed. If I remove the cover or prop it open slightly the furnace works perfectly. If I put the cover on like it is suppose to be the furnace does not ignite and faults out after three attempts.
I have carefully checked and the cover is doesn't seem to be touching any wiring or anything else in the burner area. The igniter operates properly and the gas valve opens but there is no ignition and the igniter goes back out. My only thought is maybe the cover is in some way suffocating the burner, but I would think it would there would be at least some flame. Any suggestions would be great.

Roger

crmont

upflow or downflow?

hf05

Not sure what u mean by side cover! If its the cover,covering your burners and you have a 2 pipe system,that would most likely mean your intake is plugged w/something like snow,rocks,plastic bag..etc.etc.The codes would give you a pressure switch fault..good luck..

crmont

rlelliott

It is an upflow furnace, Model GM8H.
The fault code I am getting is 1 Flash (Furnace lockout due to an excessive number of ignition attempts. (3 total)
There are 2 side covers, one for the burner area and one for the blower area. The one I am talking about is the one that covers the burners.
It only has one pipe (the vent).
The furnace is located in the basement with plenty of clearance all the way around it. There are no obstructions in the vent pipe which is shared by the hot water heater.
Also this is a propane furnace and the propane tank is 70% full.

crmont

You need to verify if the gas valve is getting 24 volts ac during ignition trial while the door is closed. Use a multi-meter set to ac volts. After the ignitor glows red you will hear another click. At that moment you should have 24 volts at the valve. If no flame is present the voltage will only last for 4 seconds so be ready. Get the furnace running first and check the voltage at the valve while it's heating to make sure your meter is set right. If you have ignitor, 24 volts and no flame, you may have a bad gas valve. If you have ignitor and no 24 volts then the control board may be faulty. Goodman is known for putting too much stress on the molded plug on the control board causing premature failure.

rlelliott

Yes there is 24 volts at the valve. I can also smell the propane for a few seconds when the gas valve opens. I don't see how a bad gas valve would explain this problem. The furnace works perfect when the side panel is off. How would putting the panel on make the valve not work. The side panel doesn't touch anything inside the burner area as I have checked this several times.
I think it has something to do with the amount of oxygen getting to the burner with the door in place.
Has anyone else had or heard about this problem and how to resolve it. I have even thought about cutting a few more vent holes in the side panel to allow more air in.

crmont

YES I AGREE IT'S NOT THE DOOR. THERE IS NO ANSWER FOR THAT.

When did the failures start? If you are prepared to cut holes I assume that you just installed the furnace and now you can't put the door on. Otherwise it's a problem that has develped and while cutting holes may help, it's likely not a long term fix.

I wonder if your gas pressure is fluctuating. check the water heater main flame and see if it looks normal. (Unless you have a gas pressure gauge, this is all I can suggest.) Turn off the water heater and any other gas appliance and see if the furnace will ignite (with the door on)

The ignitor might be failing or is out of place. With the door off the air enters the burner tubes differently than when the door is on. Low gas pressure could also explain the flame failure this same way.