Furnace Burner Keeps Cutting Off
Hello all, So I'm having an issue where the burner for my Dometic DFMD 30111 furnace keeps cutting off while it's trying to heat my travel trailer. It does still heat the trailer, but the burner cu...
Forum Discussion
This was posted in another RV forum by 'A1RVTraveler'
I am a mobile RV tech and I am going to suggest something you need to try.
The 2017-2019 Dometic Atwood furnace has been experiencing some problems with sail switches not staying closed during furnace operation. This has been especially problematic with furnaces mounted vertically.
A new sail switch was introduced that has cured the problem.
This is how I troubleshoot.
Removed the sail switch and bracket from the furnace. Leave all wires connected.
Have someone turn on the furnace.
Once the motor starts, close the sail switch with your hand and keep it closed.
If the furnace ignites and runs fine, the sail switch needs to be replaced with the new style switch.
You can not close the sail switch until the motor starts.
Let me know what happens.
Matt
PS:
The new sail switch comes with a modified bracket to allow the sail switch to travel an extra 1/32". Seems odd, but this cures the problem. The actual sail switch in not bad, just not staying closed during operation.
This only applies to 2017-2019 Dometic-Atwood furnaces with straight blade sail switches, not the angle bent sail switches.
See post #28
I am a mobile RV tech and I am going to suggest something you need to try.
The 2017-2019 Dometic Atwood furnace has been experiencing some problems with sail switches not staying closed during furnace operation. This has been especially problematic with furnaces mounted vertically.
A new sail switch was introduced that has cured the problem.
This is how I troubleshoot.
Removed the sail switch and bracket from the furnace. Leave all wires connected.
Have someone turn on the furnace.
Once the motor starts, close the sail switch with your hand and keep it closed.
If the furnace ignites and runs fine, the sail switch needs to be replaced with the new style switch.
You can not close the sail switch until the motor starts.
Let me know what happens.
Matt
PS:
The new sail switch comes with a modified bracket to allow the sail switch to travel an extra 1/32". Seems odd, but this cures the problem. The actual sail switch in not bad, just not staying closed during operation.
This only applies to 2017-2019 Dometic-Atwood furnaces with straight blade sail switches, not the angle bent sail switches.
See post #28
