[xalteridemx]

Howdy, I have a Goodman GMT070-4 Furnace that will not heat up. It did work earlier this week, but we had to cut power to the house and has since been turned back on. I don't know if the two are related.

- The thermostat will activate the furnace blower motor, and will turn it off as well.

I went to the attic to investigate, pulled the 2 doors off, and observed a single flash. The sticker reports this as ignition failure. I had my wife turn on the unit via the t-stat while I watched... the unit came on, red light went solid, however there were no flames nor smell of gas. There is a light switch wired to the unit, which I set to off, then back to on. The status light came back on solid, so we tried again, but still no flames or heat. If I'm correct, there is a black tube that runs up and down with three nozzles on it, and this should be the ignition area.

I am hesitant to go any farther into it without asking for advice. The general thinking I have seen is that Goodman units are undesirable and either the gas valve is stuck, the board is shot, or the igniter tips are dirty. Any help is much appreciated.

[Joshdta]

You say the electric was turned off in the house? Was the gas? Does the ignitor glow?

[xalteridemx]

you say the electric was turned off in the house? was the gas? does the ignitor glow?

The gas was off, but the heater did work after it was turned on.

There is no glow from any part of the unit.

[Joshdta]

If you are getting a ignition fail code, and the ignitor is not glowing I would say that you have a bad ignitor.

[xalteridemx]

if you are getting a ignition fail code, and the ignitor is not glowing i would say that you have a bad ignitor.

The thing is, it lists 3 other possible problems along with bad ignitor. Is there a sequence that this unit follows... such as if the gas isn't flowing the ignitor won't heat up?

[Joshdta]

Vent fan, pressure switch makes, then ignitor will glow. Then a click and the gas valve should open. Furnace lights, 90 seconds blower comes on.

[KC13]

This gadget should be glowing if ignition sequence has been activated. Observe operating sequence, listen for operating sounds from gas control.

[xalteridemx]

Alrighty, I'll give it another go in the morning, a bit cold up there now and a blanket will work for the time being. :)

[xalteridemx]

OK, I had a chance to get back up there and do a full check, and here's what I observed.

1. Activate furnace via thermostat
2. Right side blower or fan comes on
3. A relay click is heard around the main board area
4. A noise that sounds like gas flow comes on for about 5 seconds then shuts off.
5. Wait about 20-30 seconds, relay click is heard again.
6. Repeat steps 4 and 5 two more times.
7. Status light blinks to indicate ignition failure.

The large left blower that looks like it would feed heat to the house never comes on at any point. I found the igniter and two small push button switches. The switches seemed to be OK, but the igniter never started to glow. It is covered in carbon or just burnt.

Is this the source of the problem?

[hvac1000]

It could be a defective ignitor. You can test this item by attaching a volt meter to the two leeds that go to it. Then reactivate the furnace and watch the meter for a voltage reading. Post back with results. BTW you will have to be looking at the meter when the furnace is activated or you might miss the voltage reading since the circuit board only supplys voltage to the ignitor for a small amount of time. Also if you need to replace the ignitor also clean the flame sendor with steel wool or sandpaper to be sure it is functional.

[KC13]

Based on your description of your observations, either the ignitor has failed (more likely) or the circuit board is failing to power the ignitor (less likely).

[xalteridemx]

Well, tomorrow it's going to snow in Houston and I couldn't find the part locally that would sell to someone that isn't a dealer. Any tips on where to find this part?

[KC13]

Try furnaceparts.com, may be a kit like this. #0230K00001.

[xalteridemx]

KC13 -

I acquired the conversion kit on the net for ~$25. It just so happens that one of my co-workers worked for Goodman for 18 years and he offered to take a look at my problem.

The igniter had a hairline fracture in it.

Replaced it, and I now have heat in my home. Many thanks to all that helped and offered advice.

[hvac1000]

Glad you got it going

[KC13]

Bravo!