Question about Dometic Rooftop RV Air Conditioner

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Heater option disappeared

I don't have an option on my thermostat for the heater anymore. It's a Duo-therm model digital thermostat. I used to have the option of A/C, heater, fan and mode off on the thermostat. I don't believe that the thermostat recognizes the heater anymore. I know I have a heater and I've used it before but, when I went camping recently the option wasn't available on the thermostat. Has anyone run into this problem and what might be the fix?


David M.

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This link may help you identify what you need. What year is your trailer, & AC unit. Have a model # handy ?Have you checked your operators/owners manual ?

Posted on Aug 14, 2008

  • Mike Butler
    Mike Butler Dec 12, 2011

    Sounds like thermostat was changed and furnace wasn't hooked up either, due to wrong thermostat installed. I have a vision of someone grabbing a thermostat to change a faulty one in summer, then realizing it didn't accommodate furnace, but put it in anyway to get AC working. When you take thermostat off wall my guess is you'll find 2 more wires not hooked up, that will be furnace. Thermostat with furnace as same as other will be needed, or a separate thermostat for furnace beside that one, if method of wiring allows.



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