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  • Duotherm 4 button Comfort Control System

    Posted by John on June 21, 2017 at 1:05 pm

    Do not know how many folks have either the 4 or 5 button thermostat, but if you have them I know that you probably find them troublesome.

    Common problem either they do not work at all depending on the unit’s mood, or the operation is erratic and you end up with exactly what you do not want……like a heat pump on a 90 degree day.

    There are a few people out there who claim to be Dometic this and that and will gladly relieve your wallet of a couple hundred dollars or more for an “overhaul”. Here is the alternate fix, it does work and the thermostat will operate like a new one out of the box.

    The weak links are the switches. The switches are ITT/Canon PVA1-OA-H1. The switches run about 10 dollars for 20 switches delivered. Knowing that, take it off the wall and remove the cover, 4 small phillips screws. Probably a good idea to disconnect the phone line as well…. Break out your strongest readers, a bright light, tweezers and a jewelers screwdriver. The new switches are not going to be used, rather the brass contacts and springs from them. Start with a new one to get the hang of it and remove the top part of the switch, two little clamps in plastic. Now remove the spring and the two brass contacts. Do the same thing to the ones located on the t-stat board. Replace the bent and corroded pieces of metal with the shiny new ones. Repeat three times. Put it all back together and your Duotherm should operate as new. Now if you have previously thrown the Comfort Control System onto the ground, have stepped on it or something akin, this fix may not work, however this does work for me. Total time for repair…..25 minutes.

    I have owned this coach for more than 15 years and the life span for the thermostat seems to average for me, 5 years…….then it commences to go crazy. Earlier I would just buy another unit but since they are now obsolete one has to resort to other methods. Dometic is painful to deal with and their fix to me was not only expensive but unsatisfactory. Finally remember…go easy on the buttons, pushing harder or faster only shortens the life of the unit…..I speak from experience!

    My switch source…..Jameco Electronics, Belmont, CA. None of that 1000 pieces minimum as other sources ask.

    Have fun!

    Archived replied 9 years, 4 months ago 4 Members · 5 Replies
  • 5 Replies
  • Harry

    Member
    June 21, 2017 at 7:22 pm

    Fly Dude, where the hell have you been, welcome back?

  • Roscoeapproved

    Member
    June 21, 2017 at 9:08 pm

    Just out watering the lawn Truk….has it been long?


    Jeff and Lindsay

    91 Marathon XL
  • Roscoeapproved

    Member
    June 22, 2017 at 12:19 pm

    I doubt there will be a lot of response to this thread so I don’t think I’ll be hijacking it. But Dump Truk’s reply prompts this question: Whatever happened to Red and Dawn of Butch & Dawn fame? They always added some lively chats.


    Jeff and Lindsay

    91 Marathon XL
  • Archived

    Member
    June 22, 2017 at 6:07 pm

    I certainly did not mean to bunch up other peoples panty hose with this post however, there are a number of folks that have Duotherm 4 or 5 button controls for their roof airs. I admit that the 4 button is tickier than the 5 because of the dual button push for zone changes with the 4, they both have the same switches installed. As mentioned, its the switches that are the problem. My attempt with this post was to provide an alternative for those who have either of these units….. I do believe the 4 button was used until perhaps 2005 before the 5 button was introduced.

    Truk, now you know what I have been doing……

  • Archived

    Member
    June 22, 2017 at 7:26 pm


    l have the 5 button thermostats , works great never a problem yet.

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