# AC not working, no power to thermostat



## cnusb92 (Jul 16, 2015)

Last night the main power switch on our furnace shorted out (possibly due to condensation, we're not sure.) That problem is fixed but now the thermostat isn't getting power and AC isn'tworking. There's power to/from main power switch on furnace, and it *seems* there isn't anything else wrong in there. Still, don't want to buy a new thermostat and that not be the problem. Suggestions on how to diagnosis the problem?
AC is Rheem and thermostat is robertshaw 9420, powered by 24v (no batteries.)


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## nealtw (Jul 16, 2015)

You must have a transformer for the 24 volts, have you checked power in and out of that.


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## kok328 (Jul 16, 2015)

Is there a 5 amp fuse located on the control circuit board that blew?


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## lashron2000 (Nov 10, 2015)

So someone labeled the breakers wrong and I blew my control panel fuse. Still no power to thermostat.  Replaced transformer. It's getting power. Still no power. My unit is a 15 yearold all electric no heat pump bryant furnace. Any suggestions?  Am I missing a switch or small breaker possibly?


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## WyrTwister (Nov 13, 2015)

You have 240 VAC to the electric furnace ?  To the transformer ?  The transformer is 240 VAC in and 24 VAC out ?  Or did you buy a 120 VAC transformer by mistake ?

God bless
Wyr


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## slownsteady (Dec 9, 2015)

lashron2000 said:


> So someone labeled the breakers wrong and I blew my control panel fuse. Still no power to thermostat.  Replaced transformer. It's getting power. Still no power. My unit is a 15 yearold all electric no heat pump bryant furnace. Any suggestions?  Am I missing a switch or small breaker possibly?



My suggestion is start a new thread instead of hijacking this one. Someone can probably help, but trying to solve two issues in the same thread would just be confusing.


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