Dometic RM2351 Refrigerator not lighting with gas

Don't hold me to it, but at least on an older Dometic fridge I replaced the Thermocouple on, it connected at the Gas Valve, not at the Control Board. A Flame Sensor, I believe, would connect at the Control Board. The test described above, holding the TC tip in a flame and measuring the millivolt output, would call for a meter. Doesn't have to be expensive. The one pictured here from Harbor Freight is $3.99 on sale, and often free on a coupon with another purchase.

Hardware stores, and probably Lowe's/Home Depot, have generic TC's. So long as you can make the connection and mount the tip into the flame, a generic will work.

Thank you all for your suggestions. We won't be able to try these ideas until the weekend now, but I'm looking forward to trying to diagnose this. We generally only camp where there are no hook-ups, so we need the fridge to work! Thanks again.

Chances are that your thermocouple or your circuit board is bad. Remove the thermocouple and hold the tip in a gas flame with a multimeter across the leads set to the millivolt range. The voltage should be somewhere in the 20-30 mv range. If it is the circuit board is bad. If not in the range your thermocouple is bsf.

Depending on model year (serial numbers) the Dometic RM2351 used a 'thermocouple' and later model year uses a spark electrode (which is the flame sensor).


Your main flame is lighting off (good spark) but won't stay lite because circuit board is not getting the flame proof signal....either bad sensor (likely) or bad circuit on board

Dometic thermocouple....part #2932052018.......LINK


Dometic spark electrode....part #2932781012.....LINK


Before replacing....pull thermocouple/spark electrode (whichever one you have) clean the connection at board...make sure it's tight and clean up thermocouple. Spark electrode gap should be 1/8" and both need to be engulfed in main flame.

Also, are the thermocouple and flame sensor the same thing?

Hmmm... Thank you both so much for responding. I'll take a look at that manual and see what I can find. Also, locate the flame sensor. Is that something I can test myself?

Christy, Just saw this was Post Number One. WELCOME! Hope we can help you and you'll hang around to help others.

Thanks for posting Make/Model. Many do not and it really becomes a guessing game.

Our friend and mentor Chris Bryant (RV Shop Owner) has a lot of manuals on his website. I picked this one because I couldn't find your model number and this one was close to it. Your problem sounds somewhat like "thermocouple" in the troubleshooting but the ones I've seen do that will burn a few seconds after lighting and sparking stops. The it'll do a "re-start" since the thermostat is still calling for cooling, and repeat the cycle. If you DO replace the thermocouple that "wrench" fitting is NOT LP Gas. It's only an electrical connector so don't overtighten. But that's just a warning for futures, we aren't anywhere near that far along yet.

Robt, the manual I referenced says "thermocouple" and not "flame sensor, flame prover" etc. I don't fully understand the "sensor" but I do know that a failed thermocouple will let the gas valve flop shut once the logic board's power is removed from it after the startup cycle. Christy should be hearing a CLUNK when the flame goes out since the Valve isn't getting the voltage from the TC that it needs to stay open.

Chris, Does one of your online service manuals cover Christy's model RM2351? If so which one...

It's the flame sensor that "should" keep the flame lit. A very small voltage is generated from that flame sensor. No voltage, no flame.