Have HVAC Questions? Ask an HVAC Expert for Answers
Hi, I'm Tim and I'm an HVAC expert here to assist you with your questions. Please provide all information I request as it makes it more difficult to troubleshoot something when I'm not there onsite. Essentially, you become my eyes and ears. Thanks for the opportunity to help. At the end of our dialog, you will have a chance to rate my service, but please wait until we are finished and you're satisfied you have all the information you need.
Hello. Thanks for your time.
There are 2 basic possibilities: a bad board or a bad blower motor. I would need you to check voltage to the blower leads to confirm which it is.
all right. give me a second and i'll bring my laptop down to the furnace.
ok. so i've duct taped the switch for the door so power is currently being applied. do i need to have the thermostat set to get the correct voltage reading?
Yes, put A/C on and set temp down. The furnace blower leads should attach to the board on a terminal marked "cool" or something similar. Do you see that terminal on the board?
i see the lead connected to cool on the terminal board. there isn't any exposed metal to attatch my leads. would unplugging the wire to check the voltage work?
You could turn power off, disconnect the lead from the board and tape so it doesn't touch anything. Then with power back on, put your meter on "volts AC" and put one lead on the board terminal marked cool (not the wire) and the other on one of the white neutrals. Should read 120 volts with A/C on.
securing power and pulling lead
ok. pulled the lead and not getting any ac voltage. the status indicator on the board is red. not sure if that is what is supposed to be on there or if it indicates something wrong. ill attatch a picture
Does the blower work when you put it on fan "on" at your thermostat:?
no. fan doesn't work with on. can't try heat because it is too hot in the house for the thermostat to go that high
OK, you probably have a bad board. Sometimes when boards go bad you can tilt or turn them over and see burned areas or discoloration on the board. If you do this, turn power off. By the way, did you wait a while when checking voltage? Some boards have a slight delay built in.
yep. i just checked voltage again and nothing
So it's supposed to have run this whole time and still no voltage?
Can you see the spot where all the thermostat wires attach to the board?
yes. they are labeled r g and w i believe. the voltage on all three terminals is 5vac
Can you find one labeled "G"?
now the status light is blinking 5 times.
yes i see the G
OK, with AC still on check across the G terminal to a good ground or common (you can even use one of the neutral wires)
Let me know what you have
OK, that confirms it then, the board is bad
ok. would changing that be something I could do. Have some experience with circuit boards from my time in the navy. Or would it be better to call someone in?
It can be done. The biggest mistakes people make is not getting an exact replacement OEM board and then when changing, not marking the wires.
ok. Is there a website that I would be able to order one of the cards, or should I talk to someone at an HVAC supply/service store?
There are many sites that sell Goodman parts. If you do a Google search, you can find several. I'd check around because prices can vary a lot.
ok. Thank you very much for your help Tim. I appreciate it!
OK, good luck. Thanks for using Just Answer and please don't forget to rate my service. (bonuses are always appreciated). Feel free to post back with any additional questions.
will do, have a great day