4 Replies Latest reply: Feb 24, 2013 9:20 AM by jamesf RSS

Error E24


Hello fellow Nesters,


I have had the Nest for a few months now and it's been running great, up until last night.

Living in Florida my AC is always set to cool, only once (since i've had the Nest) did i have to switch it to heat for two days. Last night was the second time i had to enable the heat. The AC was heating fine then it stopped, after a while i checked why it was getting colder again and i noticed the error message on the Nest's display "Error E24, no power to Rh detected".


Checked the breaker box, all was ok, followed the troubleshooting on the Nest website which resulted in my info being emailed to Nest Support and a reply email asking for a callback.


As it is 1AM and i have to work tomorrow i will not have a chance to call support until friday, hoping for suggestions here in the community to see if i can resolve this myself.


Right now the AC doesn't run the fan, heat or cool, i can not do anything with the Nest showing this error. Should i put the old thermostat back (complicated mess that thing) to see if it may be a hardware issue?

Any feedback appreciated

  • Re: Error E24

    I just got the same (well similar) error: Error E4 No Power to Rh. I followed the steps here in the troubleshooting section.

    Nothing. It was working earlier. Old thermostat worked for years.. Had this on for about 3 weeks. Most all good till now...

  • Re: Error E24

    Hi JayV,


    I looked into your support case and it looks like we determined there was an issue with your HVAC system that'd need an HVAC tech to resolve.


    Please let us know if you run into any other issues.




    Charles S.

    • Re: Error E24

      Hi Charles,


      Correct, we have determined it is not the Nest that is the issue. Took off the Nest and crossed the Y1 and Rh wires together directly that should have jumpstarted the AC but nothing happened. Having an AC tech over one of these days to check out the wiring.

      • Re: Error E24


        Safety Switch for the front panel..

        Was bent just enough that all the panel removing and looking I did when installing the Nest, caused this edgy situation to appear after the panel previously only being off once a year to replace filter.. Went online and tested wires at the furnace with help of an Internet Expert site adviser and figured this one out..

        I bent the switch just a little and we are up and running.