Question about Dometic Rooftop RV Air Conditioner

1 Answer

Furnace problem I Have a 2005 Montana3295RK with a duo-therm air conditioner,suburban sf35f furnace and a dometic thermostat with remote. The problem lies with the furnace. It will not turn on, and in the rare event it does it will not turn off unless you either pull the fuse, turn the switch to the off position on the furnace or turn the gas off at the tanks. I can force the furnace to come on by pulling the fuse and then putting it back in and the thermostat does not have to be in the on position. By doing this if the propane tanks are turned on the furnace will run untill one of the 3 methods mentioned above are done.

Posted by on

1 Answer

  • Level 1:

    An expert who has achieved level 1.


    An expert whose answer got voted for 2 times.

  • Contributor
  • 4 Answers
Re: furnace problem

The problem is most likely in the control module of the roof air unit. Dometic uses the thermostat to activate and deactivate a relay in the control board of the roof ac unit whiich is just visible when you remove your air intake screen. The two blue with white stripe wires are the furnace control wires.

The furnace turns on and off by the opening and closing of relay. Most likely, the furnace control relay is stuck in the on position. On the thermostate, remove the fur wire and see if the furnace quits afrer it cycles does not quit right away. With the termostat out of the loop, if the furnace does not shut down, the problem is in the control box. They are not hard to replace but you must be careful with the live wiire from the 110 ciucuit breaker. If you are not comfortable with the repair, take it to a dealer. The part number is on the assembly box. They need to know if you have the heat srip option or whatever othert options our Roof AC has. If the furnace still runs with the blue/white wires disconnected, the furnace wires are shorted somewhere between the furnace and the AC control unit.

Posted on Dec 10, 2007

Add Your Answer

0 characters

Uploading: 0%


Complete. Click "Add" to insert your video. Add


3 Points

Related Questions:

1 Answer

Duo Therm 3109228.001

sounds like thermostat issue not communicating with relay modeule

Aug 01, 2014 | Dometic 3109228.001 Duo Therm Comfort...

1 Answer

What replace Duo Therm Thermostat 3105356.001

Can you attach a picture? Does it look like this one?

Jan 14, 2013 | Dometic Rooftop RV Air Conditioner

1 Answer

It is getting cold can you tell me how do i work the furnace part of my duo therm dometic air system

I hope this doesn,t sound patronising but i have seen people turn the themostat down to make the furnace come on obviously the thermostat has to be turned up to set for a higher tempreture , after a small time delay, should then light up.

Oct 20, 2011 | Dometic Rooftop RV Air Conditioner

2 Answers

My dometic duo-therm thermostat is no longer showing an option for my furnace.

I assume it's remote control. (comfort control) Have you tried following procedure for selecting "Mode"?

Nov 06, 2010 | Dometic Rooftop RV Air Conditioner

1 Answer

Dur-therm furnace heat controll with Dometic remote

i would suggest that you look at your thermostat,it may be to close to the furnace keeping in mind that all thermostats have a certain tempreture drop (or gain) before restarting john

Dec 28, 2008 | Dometic Rooftop RV Air Conditioner

Not finding what you are looking for?
Dometic Rooftop RV Air Conditioner Logo

931 people viewed this question

Ask a Question

Usually answered in minutes!

Top Dometic Air Conditioners Experts

Mike Butler
Mike Butler

Level 3 Expert

6674 Answers

Bill Long

Level 3 Expert

571 Answers


Level 1 Expert

46 Answers

Are you a Dometic Air Conditioner Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides