Dometic RM2400 works on AC, will light but not cool on gas

[MJGenay]

Hey all,

I have a '86 Kit Companion that we picked up last year. It seems to have been well taken care of. Everything seems to be working with the exception on the fridge on propane. I did a little digging around, cleaned the burner, office, igniter yesterday. I can get it to light and it burns with a nice, but very small, blue flame. Won't cool at all on propane but gets nice and cold on AC power. I'm a little lost on what I should be looking for. I considered that it may be a gas pressure issue but doubt that as everything else propane (water heater, furnace, stove), all work. Truly not sure and I don't want to just start throwing parts at a 37 year old TT.

[MJGenay]

I picked it up on Amazon. At any rate, I was wrong. I forgot I had it on and checked back in about 4 hours and had it nice and cold in the fridge and frost in the freezer compartment! No clue why with what appears to be the same flame size it is working now and wasn't last year or this earlier this spring, but it is. Unfortunately, or fortunately, it doesn't get hot up here. I think our record high like 40 years ago was 83. It was around 61 yesterday while I was testing it. Hoping it's still working well enough to work when we drag the camper down to the desert or anywhere lower this summer.

Thank you for the help.

[dougrainer]

MJGenay wrote:
So I finished replacing the thermostat and I still have the same issue as before. Not much of an issue getting the pilot lit off but won’t make a larger flame than the pilot. Not cooling. I haven’t tried on AC yet this year. Any other ideas?

Where did you find and get the tstat? You need to do a gas pressure test AT the refer. Doug

[MJGenay]

So I finished replacing the thermostat and I still have the same issue as before. Not much of an issue getting the pilot lit off but won’t make a larger flame than the pilot. Not cooling. I haven’t tried on AC yet this year. Any other ideas?

[MJGenay]

dougrainer wrote:
Your model refer has what is called a BYPASS LP TSTAT. That means when on LP, and you select your temp on the inside knob, the refer flame will go to "hi" when calling for cooling. When the temp is reached, the flame then goes to a smaller flame, but still blue. Since it works on 120(the mechanical point part of the tstat), the problem is a bad tstat on LP. Finding a 2400 tstat after 37 years will be difficult. I would do an extensive Google search for a Dometic RM 2400 tstat and see what comes up. A LONG shot would be to remove the tstat and attempt to clean it out. This would not affect the 120 side of the tstat. BUT!!!!!!!! If you decide to remove the tstat without having a replacement, be advised that the small capillary temp metal sensor tube that goes from the tstat to the inside metal evap fins may crack/break when attempting to remove to pull the tstat. After 37 years, that metal tube will be more brittle than new. IF that tube cracks/breaks, then the 120 side of the tstat will fail to function. Doug

Thanks Doug! I did a little searching and I may have found it however I'm going to do a little more digging before I potentially place an order for the wrong thing. I'm going to avoid cleaning as I don't want to lose my AC cooling. Thank you for the help.

[Grit_dog]

^Love your wealth of knowledge Doug. Keep it up.
For those that listen rather than argue with you, they will learn something.

[dougrainer]

Your model refer has what is called a BYPASS LP TSTAT. That means when on LP, and you select your temp on the inside knob, the refer flame will go to "hi" when calling for cooling. When the temp is reached, the flame then goes to a smaller flame, but still blue. Since it works on 120(the mechanical point part of the tstat), the problem is a bad tstat on LP. Finding a 2400 tstat after 37 years will be difficult. I would do an extensive Google search for a Dometic RM 2400 tstat and see what comes up. A LONG shot would be to remove the tstat and attempt to clean it out. This would not affect the 120 side of the tstat. BUT!!!!!!!! If you decide to remove the tstat without having a replacement, be advised that the small capillary temp metal sensor tube that goes from the tstat to the inside metal evap fins may crack/break when attempting to remove to pull the tstat. After 37 years, that metal tube will be more brittle than new. IF that tube cracks/breaks, then the 120 side of the tstat will fail to function. Doug