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Why won’t my dometic rv thermostat switch from cool to furnace ?

Make sure fan on auto

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6 Suggested Answers


6ya staff

  • 2 Answers


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Posted on Jan 02, 2017


Bill Long

  • 606 Answers

SOURCE: RV air conditioner. Compressor running, fan stops before cool

The fan motor is getting hot and going off on the internal overload in the motor.
This is caused by either a low voltage, a bad capacitor, or tight or dry bearings in the motor.
To check the bearings turn the power off to the unit, then spin the fan blade if it spins freely then the bearings are ok.
To check the capacitor you will need some kind of tester or you can buy a capacitor and replace it, that's what a lot of people do. They usually don't cost very much.
To check the voltage you will need a voltmeter and measure the volts at the unit.

Posted on Jun 09, 2009


Mike Butler

  • 6674 Answers

SOURCE: I have a DuoTherm BriskAIr 13.5K BTU. The Dometic

If you look at control box at roof unit, they usually use a separate set of wires for furnace. See what colors they are attached to at harness to thermostat. Some just follow other harness, and come out at thermostat. (bypass control box) Once you've determined which 2 they are, join them together & see if furnace starts, as it should. If it does, thermostat is faulty. If not, pull outside cover off & check voltages at furnace. I'm guessing by furnace model that your unit is approx 30 ft , but if it's a park model, you may have 24 volt system on furnace or 12 volt. Another way of confirming is to go to back of furnace where air intake grille is inside your unit, and locate 2 blue wires going to furnace & remove whatever wires are attached to them & connect them together. Furnace should start up.

Posted on Jul 08, 2009

Testimonial: "thanks for the link. info solved my problem."


  • 62 Answers

SOURCE: Dometic Rv fridge will get cold on a/c power but

does the flame ever got out if not ,the tsat is not the problem. It could be that the flame is not hot enough or the flue has a restriction

Posted on Jul 25, 2009


Frank England

  • 202 Answers

SOURCE: My dometic rv refrigerator will not cool, what are

want cool on gas ???/ elec ???? 12volt ????

Posted on Mar 27, 2010


  • 332 Answers

SOURCE: last year my dometic rv fridge would run fine on

Here is an interesting possible problem to look in to

First a bit of background on LP gas

Your LP system operates on 1/2 lb of pressure Not much more than a breath of air. Keep this in mind for a minute.

A lot of RV's have been built over the years using rubber hoses to connect LP gas to water heaters, furnaces, and refers.
Over time rubber and LP gas create an oil, if you have a low spot in your rubber line that oil will collect in the low spot - - Remember the 1/2# of pressure from earlier? Does not take a lot of oil build up to over power the 1/2 # of pressure and now you are not getting LP gas to your refer.
This is one possibility. The lines will need to be removed from the refer and other low setting items like the water heater and furnace also from the LP tank regulator and the using NO MORE THAN 10 pounds of air pressure blown out. BE VERY CAREFUL this oil is some really nasty stuff - cover the ends of the lines with a cloth in a plastic bag with some holes poked in the bag and rubber band it on.

But first lets look at some other options

Your refer has to have 12 volt power to it to operate
90+ % of all 12 volt issues are grounding problems.
Make sure you have at least 12 to 13 volts to the refer and that you have a good ground.

Next Are you getting gas flow to the burner?
If you are getting gas try changing your thermocouple They run a couple of buck and is an easy test.

If you have 12 volt power and gas have you noticed an ammoina smell?

This model has been known to lose the cooling unit
Hope this helps

Posted on Mar 31, 2010

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