Is my Dometic frig supposed to have a thermocouple?

[Landrum]

I have a RM 2551 in my 2011 23fb. On the last two trips of the season I noticed the frig wouldn't run on gas while traveling. The pilot light on my frig comes on immediately, but the spark electrode keeps sparking for a minute or so till the gas shuts off. It will go through this cycle 3 times before the check engine light comes on. I'm now trying to get it fixed before spring. After some research it seems like the steps are 1) to clean the burner, flue, etc. then 2) replace thermocouple then 3) new control board. So first stop is the manual. I know product manuals can be less than perfect, but according to the diagrams in the manual there should be a thermocouple which as I understand tells the control board the flame is lite? See photo attached. Am I missing something?

[daveswenson]

In many applications the spark probe also acts as the thermocouple, and needs to be right in the flame. I would start by adjusting the position of the spark probe and clean the jet in alcohol for good measure.

[Landrum]

Thanks. I'll give it a try. It currently is NOT in the flame.

[Landrum]

That was the problem. I probably bumped the wire (which pulled the ignitor out of the flame) when cleaning out the compartment. Thanks

[Ray Eklund]

Landrum... I think your and my RM2551 were both Factory caused problems.

The 2006 RM2551 had a separate thermocouple that was mounted over the propane flame. The 2008 manual shows the 2006 setup but, now I am told, the spark electrode is also designed to be the thermocouple. Some time after the 2006 units were made, there was a change in the system's sensing BUT used the metal brackets for the OLD SYSTEM that reduced the thermocouple function to... sporatic.

My "exhaustive blow by blow" trying to find the source of "my exact problem as yours" might have been solved by reading this original post.

Now that my unit is running without chronic resets... I may discover that it runs all of the time...

I hope the bending of the sheet metal bracket to move the tip of the spark electrode was and is the solution to this problem. Enough said.

[Landrum]

I did notice the manual on mine was wrong which had me scratching my head. Someone on the forum helped me figure out the issue. That said I caused my problem. It worked perfect for a year. I'm 99.99% sure I moved the Thermocouple while cleaning the back of the frig.

[Ray Eklund]

There is the protective cover shielding this area and the plate holding the thermocouple, at the top it has a very secure, tight fit.

I had to put plenty of effort bending this sheet metal a fraction of an inch, using a pair of pliers. You must have used a hammer to clean the fridge. Yours look factory new. Mine from sucking in dust over 8 years will never look that clean after I wipe it out after each trip. After 8 years I had nothing to clean out of the exhaust vent. Of course, we do not live in the AS and would not have expected much "scale or carbon" residue.

But... no matter... we seem to have found a common cure. The fridge has now operated 24 hours without needing to be reset. If someone else did not touch this thermocouple and finds the bending of the bracket fixes the problem... you are due a pardon by the RM2551 Vigilantes!