Coleman furnace

[captjrc14]

Gentlemen,

I have a Coleman Evcon Model DGAT056BDF Serial # 980998509 that is experiencing a rash of problems. Initially the diagnostic code indicated the combustion switch failed to close (3 flashes). I removed the switch and the induction motor and ordered both parts from your website. I re-assembled the switch and motor while waiting for the parts to be delivered and the furnace began to work again. When the parts arrived the combustion switch only had a single vacuum tube connection (mine has 2) and when I called your company a representative advised me that Coleman had replaced that part number. I kept the motor with the belief that the motor was probably the source of the problem and returned the combustion switch. The furnace worked for a couple of weeks and then it malfunctioned again, this time with an ignition failure code. Everything works up to the point of ignition and through the glass I can view that the igniter does not glow.

My questions are:
1.Is it likely that I have another problem perhaps in the board, etc? Or is it just coincidence that now the ignitor has gone bad too? Is the ignitor relatively easy to replace?
What would you recommend?

Thanks

[Robert]

Hi,

Not sure which pressure switch you received, but the replacement switch does have a different p/n, but also has the two vacuum ports. Sorry for the wrong part and misinformation.


For the ignitor, there is often more than one problem that arise at same time, sometimes tied together.

In this case, the pressure switch and/or inducer motor problem would override the ignitor problem until it was resolved.


Test at the ignitor leads connector to see if you are getting 120VAC to the ignitor at correct time and it should remain for 30-40 secs give or take a few.



Thanks,
Robert

[captjrc14]

Robert,

Thank you for the reply. No apologies needed for the part deal, I was just going by the picture on the website and the old part number, no one could have foretold that Coleman had discontinued it and cross referenced it.

Back to the furnace though, I may have been confusing in my description. Now the inducer motor comes on and blows for the required time and the gas valve opens but cuts off when ignition fails. The only evident problem now is the ignitor is not glowing. I will test the ignitor leads with my meter tomorrow (the furnace is at another location) to ensure that there is 120VAC per your instructions.

Thanks

[Robert]

HI,

What I was saying is that the ignitor could have been going bad earlier, but the inducer motor problem/pressure switch problem would override it and diagnostic light would show that first.

Once you corrected that and got it going again, the ignitor problem surfaced on diagnostic light.

IF it gets the 120vac and does not glow, it is bad.



Thanks,
Robert