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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I just installed a NEST thermostat. It comes up with code

Customer Question

I just installed a NEST thermostat. It comes up with code E72. I contacted the support team and spent several hours on the phone with them trying to fix problem. It seems that I have two power wires and Nest only works with one. I have Rc and Rh. I tried taking one out and that didn't work came up with code R73. Then tried changing red wire from Rc to Rh without other wire attached that came up with code E74. Help
JA: Just to clarify, do you think this is a larger HVAC problem, or something specific to the thermostat?
Customer: My previous thermostat worked perfectly fine with the wiring. So not an HVAC problem it is a nest problem
JA: Do you plan on doing the work yourself?
Customer: Yes I had done the previous and would like to fix myself if possible
JA: Anything else we should know to help you best?
Customer: No that is the only item that isnt working. Everything else went in okay when entering info into nest program
Submitted: 8 months ago.
Category: HVAC
Expert:  HVAC Guru replied 8 months ago.

Hello, one minute while I get some information together.

Expert:  HVAC Guru replied 8 months ago.

Hello and thanks for using this service! If you are a JA Member I would like to personally thank you and welcome you back! I am HVAC Guru an extremely experienced tech on the site and I try to get to as many customers as I can. NOTE it takes time for me to type research and add links so please wait for me to respond back I can only do this so fast. Secondly, I do not know your skill level so please try and let me know if I am going beyond your knowledge or comfort zone thanks! I strive for a 5 star rating from everyone especially our JA members.

Do you have a volt meter?

Customer: replied 8 months ago.
Customer: replied 8 months ago.
Please cancel my request for assistance and cancel billing on my Visa immediately

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