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HVAC Guru
HVAC Guru, HVAC TECH
Category: HVAC
Satisfied Customers: 14141
Experience:  15yrs in the HVAC industry with certificates and degrees.
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I have a Goodman gmt070-3a furnace. It is not igniting to

Customer Question

I have a Goodman gmt070-3a furnace. It is not igniting to blow hot air. The gas is on in the house but the igniter never glows. I've replaced the igniter with 2 different igniters and still no luck. What else could it be?
Submitted: 1 year ago.
Category: HVAC
Expert:  HVAC Guru replied 1 year ago.

Hello and thanks for using this service, if you have been waiting do not worry or get upset I am just one of the techs on here and I try to get to as many customers as I can and I just picked up your question now. Please give me time to respond sometimes I get your replies late so there may be a significant delay in responses. Please be patient and often I will ask you questions to narrow down the issue to get is diagnosed correctly.

Have you checked the rollout thermostats around the burner area. One of them could be tripped open causing this issue. Some have a reset button on them and others do not. They all have to be closed in order for it to work properly. Start there and let me know what you find.

They would look like this

CLICK HERE

We are on the honor system for our time, all I ask is please rate my service using the STAR RATING LINK on your page before you leave. If you are not happy with the service please let me know before leaving a negative rating. This is the only way I am paid or credited through the site for my time. This will also allow you to get directly back to me for FREE follow up questions and tips are greatly appreciated! Thanks

Customer: replied 1 year ago.
I don't see one. Can I text you a pic?
Expert:  HVAC Guru replied 1 year ago.

Yes

CLICK HERE'

Or this one

CLICK HERE

Expert:  HVAC Guru replied 1 year ago.

You can upload a pic here with the paperclip attachment

Customer: replied 1 year ago.
I think the 2nd one you have up there may be it. There are two of them in there
Expert:  HVAC Guru replied 1 year ago.

Yes press on the button in the middle and see if one clicks, then try it. Let me know

Customer: replied 1 year ago.
They don't really have a button to push. Pictures attached
Expert:  HVAC Guru replied 1 year ago.

Those two right in the front with the blue reset buttons.

Customer: replied 1 year ago.
Ok they dont seem to depress but tried it. Still not working. Ignitor never glows
Expert:  HVAC Guru replied 1 year ago.

Ok does the exhaust blower come on and run?

Customer: replied 1 year ago.
Kicks on, blows for about 30 secs, which used to be when the ignitor would glow then ignition.
Expert:  HVAC Guru replied 1 year ago.

OK have you tested for power at the ignitor leads?

Expert:  HVAC Guru replied 1 year ago.

Also are you getting any error codes on the board?

Customer: replied 1 year ago.
I have not tested the leads. Do you mean those on the harness going to the ignitor? Also, how do I know if there's an error on the board?
Expert:  HVAC Guru replied 1 year ago.

Yes the leads to the ignitor check them for power. You should have a flashing error message on the board leds.

Customer: replied 1 year ago.
I have a fluke 75 multimeter but not sure what setting to test the leads??
Expert:  HVAC Guru replied 1 year ago.

Set it to AC VOLTS 200 range and put it across the two leads to the ignitor and start it up ...after the inducer comes on what does it read?

Customer: replied 1 year ago.
ok so just connect to the leads and start the furnace?
Expert:  HVAC Guru replied 1 year ago.

YEs put your meter leads across the two to the ignitor and start it up see what you get on the meter

Customer: replied 1 year ago.
65
Expert:  HVAC Guru replied 1 year ago.

Ok well that is like half power so you may have a board relay issue it sounds like it. Do you get nothing then it goes to 65 ?

Customer: replied 1 year ago.
nothing flashing on the board
Expert:  HVAC Guru replied 1 year ago.

OK if nothing is flashing on the board at all and you only have 65 volts to the ignitor I would say the board is bad. Can you remove the board and check the backside for any burn marks?

Customer: replied 1 year ago.
now the red status light comes on as usual, the blower kicks on, I hear the click like the ignitor should come on but it doesn't. Would all of that still occur if the board was bad?
Expert:  HVAC Guru replied 1 year ago.

The joint on the relay for the ignitor may be bad, the relay for the ignitor is on the board though

Customer: replied 1 year ago.
Ok. So what do I do next?
Expert:  HVAC Guru replied 1 year ago.

I would check the backside of the board where the relay for the ignitor is, see if one of the solder joints is bad. Or replace the board on the unit.

We are on the honor system for our time, all I ask is please rate my service using the STAR RATING LINK on your page before you leave. If you are not happy with the service please let me know before leaving a negative rating. This is the only way I am paid or credited through the site for my time. This will also allow you to get directly back to me for FREE follow up questions and tips are greatly appreciated! Thanks

Customer: replied 1 year ago.
could it be the flame sensor?
Expert:  HVAC Guru replied 1 year ago.

Not if the ignitor never glows

Customer: replied 1 year ago.
ok. how about the harness from the board to igniter harness? do those ever go bad?
Expert:  HVAC Guru replied 1 year ago.

It could, you should then check for power right off the board to the ignitor to see if you have 120 if so then maybe a wire issue.

Customer: replied 1 year ago.
Here are pics of the back of board. I don't see any burns, you?
Expert:  HVAC Guru replied 1 year ago.

A couple joints look overheated....but nothing else. Can you check power off the board to the ignitor to confirm you are not receiving correct voltage?

Customer: replied 1 year ago.
Sure. Although I'm not sure how to really
Expert:  HVAC Guru replied 1 year ago.

Do you see the ignitor wires that go to the board?

Customer: replied 1 year ago.
if the joint on the relay is bad then the whole board needs replaced?
Customer: replied 1 year ago.
Now it won't kick on at all. Not sure why....the red light on board is on but unit doesn't kick on
Expert:  HVAC Guru replied 1 year ago.

I think there is an issue with that board for sure, nothing else really would cause that issue.

Customer: replied 1 year ago.
I've now replaced the ignitor and the board and the ignitor still does not glow during the process to kick the unit on. What other suggestions do you have? I'm $200 in parts at this point. Thanks
Expert:  HVAC Guru replied 1 year ago.

Does the inducer fan come on and run?