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Tim H.
Tim H., HVAC Professional
Category: HVAC
Satisfied Customers: 3971
Experience:  Experienced in all aspects of HVAC, both residential and commercial.
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No power to the programable thermostat

Customer Question

No power to the programable thermostat
Submitted: 1 year ago.
Category: HVAC
Expert:  Tim H. replied 1 year ago.

Hi, I'm Tim and I'm an HVAC expert here to help answer your question(s). Please provide all the information I ask for since I'm not onsite. At the end of our dialog you will be asked to rate my service, but please wait until then and all your question(s) have been answered satisfactorily. Thanks for your business!

What kind of furnace is this? Make and full model number? Did you wire in the common wire?

Customer: replied 1 year ago.
I'm actively looking for the model number but it is a Carrier and I hooked up the White, Red, Yellow, and Green wires because those were the only ones wired into the original thermostat
Expert:  Tim H. replied 1 year ago.

OK, well I do need the make and model of the furnace. Did you have furnace power shut off when you did the wiring? Becuase if you did not, you may have blown a fuse on the furnace control board.

Customer: replied 1 year ago.
Carrier WeatherMaker Infinity
Expert:  Tim H. replied 1 year ago.

OK, here's what I'd like you to do. Take the Nest off the wall exposing the wiring. Get a voltmeter and set to "volts AC" and put one probe on the red wire at R and the other proble on any other terminal. If the furnace has power, you should read 24 volts (AC). Let me know the results.

Customer: replied 1 year ago.
The power was on when the wiring was changed I'm looking but I don't think I have a voltmeter
Expert:  Tim H. replied 1 year ago.

If you don't have one, perhaps you could borrow one from a friend? Or you can usually find a quality meter for under $25 at most home improvement or hardware stores.

Expert:  Tim H. replied 1 year ago.

Let me know if you have additional questions on this.

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