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How to tell if I have a millivolt system

I'm looking into getting a Nest, and I've got different answers from 4 different people from Nest about whether or not it would work with my system. The last person I spoke to said it won't work because I have a millivolt system, but I don't think I do. The previous homeowner, who replaced the HVAC system, didn't leave the manuals and I can't find them online. My heating system is a Warren electric heater (model number WGO 0802B) inside a Goodman air handler (model number ARUF182416B). I also have a First Co A/C (model number 18WCU-10BB). The heater and A/C each have a separate breaker switch.
Can anyone help me out?


  • nicholas bonham-carter
    I don’t think you have a millvolt system, such as would be on an older boiler, but you will have other problems with the control wiring of the Nest (of vipers).
    What sort of thermostat is controlling your system now? What is the desired result of your changeover to the Nest?—NBC
  • merrydeath
    merrydeath Member Posts: 2
    I have a Honeywell CT51A. The one thing that all the Nest people agreed on was that the wiring will work.
    I want to have something I can control from my phone, because I always forget to turn down the heat when I leave. Also, the Honeywell doesn't seem to regulate them temperature of my house very well. It'll get super cold, then the heat will kick on and stay on until I'm sweating, then it'll turn off and stay off until it's super cold again.
  • Jamie Hall
    Jamie Hall Member Posts: 23,415
    Well, if you can solve the wiring issues -- which are going to be interesting... the Nest will probably work. Almost as well as the Honeywell does, assuming that someone bothered to properly adjust the Honeywell (it's not adjusted properly -- that's the cause of the temperature swings. Not the fault of the thermostat).

    Always assuming, that is, that you want the manufacturers of the Nest (and quite possibly your utility company) to have full control of your heating and cooling whenever they want, and full knowledge of when you're home...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Fred
    Fred Member Posts: 8,542
    You don't need a wifi thermostat because you keep forgetting to turn the thermostat down when you leave for work. You just need a programmable thermostat that you program once for each day of the week and you walk away from it, forever, or until it needs a new battery, whichever comes first. :)