Have HVAC Questions? Ask an HVAC Expert for Answers
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?
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.
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.
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.
Let me know if you have additional questions on this.