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 cuts out, then comes back on, then cuts out again, then comes back on. It will eventually get over whatever the issue is and stay on until it reaches temperature, but it goes through this issue every time the furnace turns back on. The blower fan stays on the whole time and there's no error light from the control board when the burner goes out or comes back on.
The following are the things I've checked or considered so far:
- During my first winter, I learned that one of the wire connectors to my sail switch is a bit loose and I figured out how to get it to stay in contact, so that was my first thought, but that doesn't appear to be the problem. I just checked it for dirt/debris and it's totally clean...and last time the error light came on when that connector was the problem but I'm not getting any error lights now and the burner does cut on normally.
- The furnace is mounted vertically in a very open compartment under my entertainment center and I can't find a specific return air vent in my travel trailer for what most people would have as an open air return. The manual says it gets return air from the openings in the case (which are many), and I didn't have this issue last year, so I don't believe it is a return air flow problem.
- I just had to replace my propane regulator for the second time, but a windex leak test doesn't produce any bubbles, and the problem started before I replaced it, so I don't think that is the issue.
- One of my searches indicated that a bad thermostat could be a problem, but the unit does heat normally aside from the burner cutting off prematurely. As stated before, the unit eventually stays on until the heat cycle is complete, so I'm not sure it's a thermostat problem unless there's some other consideration with those that I'm not aware of.
I'm not really sure where to look next. Internet searches bring up the issues I've listed above, but I'm suspecting it's some sort of internal problem that requires disassembly of the unit. I'd hate to pull the whole thing out and take it apart only to find out it was something stupid I didn't know about and disassembly wasn't necessary.
Has anyone else had issues like this and found a simple solution? Or is it likely a clogged burner or some other internal problem and I have to take the whole thing apart?
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 cuts out, then comes back on, then cuts out again, then comes back on. It will eventually get over whatever the issue is and stay on until it reaches temperature, but it goes through this issue every time the furnace turns back on. The blower fan stays on the whole time and there's no error light from the control board when the burner goes out or comes back on.
The following are the things I've checked or considered so far:
- During my first winter, I learned that one of the wire connectors to my sail switch is a bit loose and I figured out how to get it to stay in contact, so that was my first thought, but that doesn't appear to be the problem. I just checked it for dirt/debris and it's totally clean...and last time the error light came on when that connector was the problem but I'm not getting any error lights now and the burner does cut on normally.
- The furnace is mounted vertically in a very open compartment under my entertainment center and I can't find a specific return air vent in my travel trailer for what most people would have as an open air return. The manual says it gets return air from the openings in the case (which are many), and I didn't have this issue last year, so I don't believe it is a return air flow problem.
- I just had to replace my propane regulator for the second time, but a windex leak test doesn't produce any bubbles, and the problem started before I replaced it, so I don't think that is the issue.
- One of my searches indicated that a bad thermostat could be a problem, but the unit does heat normally aside from the burner cutting off prematurely. As stated before, the unit eventually stays on until the heat cycle is complete, so I'm not sure it's a thermostat problem unless there's some other consideration with those that I'm not aware of.
I'm not really sure where to look next. Internet searches bring up the issues I've listed above, but I'm suspecting it's some sort of internal problem that requires disassembly of the unit. I'd hate to pull the whole thing out and take it apart only to find out it was something stupid I didn't know about and disassembly wasn't necessary.
Has anyone else had issues like this and found a simple solution? Or is it likely a clogged burner or some other internal problem and I have to take the whole thing apart?
