GMH80453ANAB furnace that will not ignite injectors . has me stumped.

been working on furnaces for over 25 years , and don't get stumped . especially a goodman. I've ran out of ideas . goes thru the cycle ,and ignitor comes on , then goes off. gas valve kicks off. wont lite. new board , tried 3 different gas valves, cleaned everything including injectors. I can light it using a lighter. the home owner says the gas company hasn't been in the neighborhood . I even took orafices out , and looked for blockage. called goodman. they said it has to be dirty injectors. nope, I cleaned them also. getting 26-27 volts to gas valve. only thing I haven't been able to do is check gas pressure coming in to valve , or out because the set screws are smaller on this valve. I told the homeowner to call gas company to see if anyone was working in the area around the day his furnace quit lighting. the ignitor is in a strange spot . it sits between the 2 injectors toward the front , and don't see how the gas seeps to the ignitor to light. it worked beforehand. anybody have any ideas on what to check, or has experienced this problem before ? it's a new one on me.

 

Does that mean it opens and closes ? Does it release gas ?

Injectors ?? Do you mean burners ?

 

oh yea. I lite the furnace with my lighter at the orifice. I talked to a friend of mine that's more service oriented last night. he told me its the gas pressure . he went thru the same as me his first time with this problem. that I might have to put a regulator on it. we'll see.

 

yes. that valve opens , don't light , then glowbar kicks off . I say burners, but no burners anymore . burners burn gas up. injectors burn gas horizontal. just mixin words. its all the same .

 

I tend to agree it's a gas pressure problem. If it's incoming or thru the valve is another matter.

 

the problem I have now is that where you put your monometer tip is too small. and the goodman dealer doesn't have the part to go on it. gas company came out and checked pressure. said its getting 5 w.c. like its suppose to. so I take it no one has had this problem before ? if I get it working, i'll say in here when I do.

 

I'm sure all the gas company checked was incoming gas pressure. You certainly should be able to fabricate some kind of adaptor to hook up your manometer.

 

guy from goodman in texas says to take the screw out and put your rubber hose right up on the stub. it worked, I got between 3-4 w.c. going thru the valve. now im really stumped. can an ignite work, and be bad at the same time ? its a stick igniter and when it comes on , its not the same color orange thru the stem. the first 1/4 to 1/2 inch doesn't even turn color. stays black. about 2/3 down its bright orange , with a duller orange on each side of it. goodman guy says the whole stem should be hot orange. but mines not. ive only seen where they either glow or don't.

 

also getting 122 volts to ignitor.

 

Ignitors are pretty cheap. I'd replace it. How long is the ignitor getting the 122v & how long does Goodman say it is supposed to be?
Has the board been replaced? If so, maybe the warm up time on the new board is shorter than the original.
If the ignitor has been replaced, some ignitors have longer warm up requirements than others.

 

the ignitor is good. the board was replaced. I solved this issue by moving the ignitor by the left orifice inside the injector. works good. not a lot of room but it works, and the guy is happy the furnace is working. goodman was no help as usual. CASE CLOSED.......thanks for any suggestions ive received. all goodman told me was to replace parts. I wasn't gonna replace any more parts just to eliminate that part. he had to keep the board , but I could of got the money back if I raised hell, but I figured sooner or later he would need it. so if anyone ever runs into this problem, just move the ignitor. saves a lot of time.