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airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8052
Experience:  Furnace, A/C and heat pump specialist.
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We lost power last night due to a storm. When power was restored,

Customer Question

We lost power last night due to a storm. When power was restored, the AC never came back on. I tried turning the thermostats to "off" and turned the breaker off and on.
Submitted: 1 year ago.
Category: HVAC
Expert:  airheatman replied 1 year ago.
If indoor fan nor ac will come on it is possible lightning got the control board on indoor unit.Troubleshooting often requires meters and test equipment.Do you have a multi meter for testing voltage? If not you can get an inexpensive one at Walmart for about 15 bucks, if you have or would like to obtain a meter to troubleshoot , I will be happy to guide you.Without a meter , there are a limited number of things we can check if you are able to do a visual inspection and can do some hands on troubleshooting.Please let me know and we can go from here.
Customer: replied 1 year ago.
I have the voltage tester, but I am 99% sure that lightning did not hit near my house.
Expert:  airheatman replied 1 year ago.
OK give me model on indoor unit and lets start at the furnace or air handler troubleshooting.I will guide you step by step.
Customer: replied 1 year ago.
Expert:  airheatman replied 1 year ago.
THis is model on your outdoor unit.I need to know model on the furnace or handler inside
Customer: replied 1 year ago.
Sorry, it is G61MPV-36C-090-06
Customer: replied 1 year ago.
There are two green lights blinking on the circuit board. One is DS1 and the other is DS2. There is also a solid yellow light labeled HI/LO. There is a green light that is not illuminated labeled ON/OFF. Finally, there is a green light labeled CEM that is faintly flickering.
Expert:  airheatman replied 1 year ago.
Tell me about the flashing on Led1 and on led2 . Are they slow, rapid, alternating?
Customer: replied 1 year ago.
Every second in unison. So not too fast.
Expert:  airheatman replied 1 year ago.
OK the ON/OFF must be on in heat or cool mode,Are you currently calling for cool at thermostat?
Customer: replied 1 year ago.
Expert:  airheatman replied 1 year ago.
OK on call for cool the ON OFF led should be ON.I would remove R,Y and G at thermostat and twist them together. Blower and outdoor unit should come on.If it does issue is in thermostat,if not issue is most likely board.
Customer: replied 1 year ago.
If I have two thermostats and neither of them make the AC run, then we can assume the problem is already at the circuit board, correct?
Expert:  airheatman replied 1 year ago.
Are you saying you have tried two different thermostats or you have two thermostats controlling different zones?
Customer: replied 1 year ago.
I have 2 zones, one upstairs and one downstairs. Neither of the thermostats makes the AC run when turned on.
Expert:  airheatman replied 1 year ago.
OK normally one of the thermostats will control the unit and the other determines if that zone should be open. I would find which one is main thermostat(it will have more wires attached) and try the connecting R,Y and G to see if unit will come on before we condemn the board,
Expert:  airheatman replied 1 year ago.
If connecting those wires does not bring on fan ansd outdoor unit I suspect the board,The DS1 and Ds2 slow binking indicate all is normal (No limit,pressure switch or anything open .So we should be getting blower and outdoor unit.Board could have taken a surge not necessary lightning when utility company restored power.