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airheatman
airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8030
Experience:  Furnace, A/C and heat pump specialist.
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Went to turn on our AC yesterday and it wouldn't come on. Hubby

Customer Question

Went to turn on our AC yesterday and it wouldn't come on. Hubby checked a bunch of things and discovered that there were no lights on on the furnace either. Fuses were fine and so was the breaker!
Submitted: 9 months ago.
Category: HVAC
Expert:  airheatman replied 9 months ago.
Do you have a volt meter for testing and troubleshooting?
Customer: replied 9 months ago.
No!
Expert:  airheatman replied 9 months ago.
OK there are a few things we can do without a meter.but you can get a cheap one at Walmart for about 15 bucks if we do not get anywhere without one if interested.First remove top panel and give me model on furnace.It will be on a label on inside panel and begin with letter R .Something like RGPH07EAUER or similar
Customer: replied 9 months ago.
Okay! Hold on,please!
Expert:  airheatman replied 9 months ago.
take your time
Customer: replied 9 months ago.
GMNT100-4B
Expert:  airheatman replied 9 months ago.
OK this is not a Rheem furnace,It is a Goodman. Now look on the control board in blower compartment and see if there is a small purple 3 amp auto type fuse. remove it and see if it looks burned.http://i.imgur.com/90juVsc.pnghttp://i.imgur.com/kYe4Epz.png
Expert:  airheatman replied 9 months ago.
Should be on corner of your board
Customer: replied 9 months ago.
It looks good!
Expert:  airheatman replied 9 months ago.
OK .With door button held in or panel in place does that little light come on on the board?
Customer: replied 9 months ago.
Yes, it does!
Expert:  airheatman replied 9 months ago.
OK if you turn thermostat to FAN ON will blower come on?
Customer: replied 9 months ago.
No! That's the mystery!!
Expert:  airheatman replied 9 months ago.
Lets do this. On the control board you will see terminals R,G,W, Y and C. Take a pair of needle nose pliers or a jumper wire and jump R and G and see if blower comes on (Door button held in of course)
Customer: replied 9 months ago.
Okay, just a minute please!
Expert:  airheatman replied 9 months ago.
Standing by
Customer: replied 9 months ago.
That's a negative!
Expert:  airheatman replied 9 months ago.
OK if we have a light on board that indicates board is getting power. If jumping R and G does not bring on fan that indicates we are not getting 24 volts out of the board to thermostat. So issue will be one of two things.1. Transformer is bad. Getting 12ov in, but not sending 24v out or2. Board is bad.You will need a meter to check for 24 volts out of transformer to determine which one.
Customer: replied 9 months ago.
Where is transformer located?
Expert:  airheatman replied 9 months ago.
Usually located close to the control board.It will have a white and black high voltage wire going in and either a red and blue or 2 yellow low voltage wires coming out
Expert:  airheatman replied 9 months ago.
See diagram below.We should have 120v in and 24v out at transformer
Customer: replied 9 months ago.
We got the fan to cycle!
Expert:  airheatman replied 9 months ago.
OK that means transformer is good. What did you do?
Customer: replied 9 months ago.
Held it longer this time!
Expert:  airheatman replied 9 months ago.
OK now touch R and Y and see if outdoor will come on (If Y wires are connected to board)
Customer: replied 9 months ago.
Don't see y
Expert:  airheatman replied 9 months ago.
OK Lets go do it at thermosat
Customer: replied 9 months ago.
Okay!
Expert:  airheatman replied 9 months ago.
Makes sure door is on furnace or button is held in
Customer: replied 9 months ago.
We're ready
Expert:  airheatman replied 9 months ago.
R and Y should bring on outdoor unit
Customer: replied 9 months ago.
On the thermostat nothing is marked! He jumped eveything on there and nothing.
Expert:  airheatman replied 9 months ago.
I am about to leave for the evening, Would you like to continue this tomorrow or would you like me to open to other experts so you don't have to wait?
Customer: replied 9 months ago.
Continue tomorrow, please!
Expert:  airheatman replied 9 months ago.
Sounds good. I have an installation in the morning but will check in when I get back, What is your schedule tomorrow?
Customer: replied 9 months ago.
Hubby will be at work until 5:30pm!
Expert:  airheatman replied 9 months ago.
Great. If you could grab a cheap meter that would be of great help to us. http://www.walmart.com/ip/Innova-3300-Equus-3300-Hands-free-Digital-Multimeter/14644665?reviews_limit=10&
Expert:  airheatman replied 9 months ago.
I will check in tomorrow evening.Just come back to question
Customer: replied 9 months ago.
Okay, fhankt!
Expert:  airheatman replied 9 months ago.
Let me know when he is ready
Customer: replied 9 months ago.
We are ready to continue!
Customer: replied 9 months ago.
Hello!
Expert:  airheatman replied 9 months ago.
Sorry I have been out of office and just stopped by.I will be here tomorrow if you can continue then.
Customer: replied 9 months ago.
We can continue Monday evening!
Expert:  airheatman replied 9 months ago.
Sounds good