Question about Dometic Rooftop RV Air Conditioner

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I have a Dometic duotherm unit on a 2005 motorhome - actually 2 units with dual zones. The problem started last year with the rear unit icing up and having some issues with not turning on and off at appropriate times based on the temp. I relocated the sensors from the factory locations and that got better, I also figured out that if I let the air flow from the ducting rather than from the main unit it didn't ice up and drip as much. Although I didn't get it checked out last year like I should have, I am having more problems this year but with the heat pump & furnace side.
The problem is that the rear unit is triping the breaker and running very hot, the air coming out of the roof unit is as hot if not hotter on heatpump setting than it is on furnace setting. In addition, even though the front unit is set on HP the furnace comes on sometimes instead, the outside air temp. is well above the level that would cause the furnace to activate normally. I have cleaned the air filters with no improvement. Any advice would be appreciated.

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Sorry I'm not familiar with this brand. I recently acquired an RV from a real estate deal. My sellers couldn't take it with them to Montana so they sold it to me for $500 when they're house sold. I'm excited to get it running. It's supposed to have a fairly new AC unit but the engine isn't running. Good luck with yours.

Posted on Sep 16, 2014


You should check with Dometic or your manufacturer we are told that there was a recall on the Dometic Air Conditioners, although we never received a recall notice. Our Dometic Air Conditioner caught on fire burned up on our RV.

Posted on Apr 09, 2008

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Ice on the coil is caused by 3 things; 1, low freon charge. 2, inadequate air flow across the coil, this can be a filter or dirty coil (I think you addressed these) or the fan isn't blowing enough air over the coil. 3, the unit is running continuously. A heat pump has another cause, that is something defective in the defrost system, like the sensor, reversing valve, control board or relay. If the breaker is tripping its because the compressor is over amping. There can be an obstruction blocking the fan or something like #2. Or the compressor is going out. If the breaker doesn't trip on other settings, like cool, but trips on heat, then I would look at the airflow.

Posted on Mar 14, 2008

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