Goodman furnace not turning on

amgill1

New board and transformer. Power to the board but no activity, no light at all. What else could be the cause?

EdTheHeaterMan

Many things. it all depends on the model number. and if the wires are connected correctly, and lots of other stuff. I hope that was not too technical to understand. I can sometimes talk over a non professional's head.

What was the part number of the board?
What is the model number of the goodman?
How old is the goodman?
Was the board and the transformer professionally replaced or is this DIY?

amgill1

Wiring wasn’t a problem, very straightforward. Same readings and scenario as before parts were replaced. Solar company added another electrical panel then no more furnace when they turned the power back on. GMS80904BNCA is the model number. Going to be a week before anyone else can come out for a second opinion. The last guys diagnosis was wrong so just trying to get some ideas as I’m all out of them! Thanks in advance 

amgill1

Board part number 50A55-743 (Emerson)
Furnace model Goodman GMS80904BNCA
It's about 12 years old but was just checked out 3 weeks ago in prep for winter and was in “perfect shape”.
The solar company sent a Local HVAC tech who basically came out and told me what parts to replace. Repair was DIY

109A_5

Hello @amgill1,

Divide and conquer, is there 24 VAC at the secondary of the Transformer ? Any Fuses ? Check limit and safety switches. See Red question marks on drawing.

HVACNUT

You're leaving something out. Why was the board and transformer replaced? 

WMno57

amgill1 said:

was just checked out 3 weeks ago in prep for winter and was in “perfect shape”. The solar company sent a Local HVAC tech who basically came out and told me what parts to replace.

What did the solar company do to your electrical panels? Is neutral bonded to ground in the main panel and ONLY the main panel. There is a well known problem with furnace igniters and portable generators where the igniter doesn't work because neutral is not bonded to ground in some portable generators.

pecmsg

amgill1 said:

Board part number 50A55-743 (Emerson)
Furnace model Goodman GMS80904BNCA
It's about 12 years old but was just checked out 3 weeks ago in prep for winter and was in “perfect shape”.
The solar company sent a Local HVAC tech who basically came out and told me what parts to replace. Repair was DIY

Was in perfect shape yet let's change these parts?

Where's your service provider?

pedmec

Did you check to make sure you had 120 volts at the service switch?

Jamie Hall

Almost always if a problem arises after someone did something, it's something about what they did. In this case, likely nothing to do with the furnace at all, but something wrong with the solar power installation. Which wouldn't surprise me a bit.

So... you really have two choices. Get the solar power company back and have them make sure that their installation didn't mess up something (like the grounds and neutrals, as mentioned), or get a qualified electrician in to do the same thing.

109A_5

Hello @amgill1,

amgill1 said:

New board and transformer. Power to the board but no activity, no light at all. What else could be the cause?
The solar company sent a Local HVAC tech who basically came out and told me what parts to replace. Repair was DIY

My guess from here is that the Solar company inadvertently cut the thermostat wires causing "no activity, no light at all". The additional new overabundance of Photons did not hurt anything.

With the dead furnace complaint the Solar company sent out a Tech that did virtually nothing except suggest what to load the 'Parts Cannon' with. @amgill1 loaded and fired the 'Parts Cannon'. And not unexpectedly it did not fix the situation.

@amgill1 you need to get a multi-meter for yourself or a Tech, Electrician, handy friend etc. that can actually spent 10 Minutes doing actual real electrical troubleshooting. Then you will know what part to actually change or repair to return the furnace to operation.

HomerJSmith

Yes, why the board and transformer replacement??? I would take a volt meter and measure the incoming voltage at the receptical. Has any other electrical anomalies occur in anywhere else in the house? Always, a dropped neutral will allow 220V to travel thru joined 115V circuits even if temporary. That would do a number on your Goodman. One would expect light bulbs, etc to burn out on other circuits.
115V circuits are joined thru the neutral conductor (the white wire).

New board and transformer. Power to the board but no activity, no light at all. What else could be the cause?

You probably blew out the new transformer & board. If that furnace has an induce draft motor, that's probably dead, too.

That will give you something to think about and check.