RM2652 Burner Will Not Stay Lit

[762x51]

I have a RM2652 in my 1998 Airstream and the gas burner will not stay lit. It will come on for about 15-20 seconds and then go off.

The refrigerator had a 2932770.01 circuit board and thinking that was the problem I ordered the universal replacement board 3308741.002 and installed it but the problem still exist.

I have measured the burner thermocouple voltage with a Fluke multimeter and it reads 27.5 millivolts and the burner has a nice blue flame.

Note: I made the mistake of reading the voltage with the T/C disconnected from the circuit board. You should take the reading with the T/C connected to the board. See my 8/31/16 post below.

Any suggestions as to what may be the problem?

Thanks in advance for any help with this problem.

[richj]

I measured the voltage with the thermocouple out also. I believe for the RM2652 you have a 2-wire thermocouple. Mine is a solid piece that screws directly into the safety valve.

[762x51]

I made the mistake of reading the thermocouple voltage with the T/C disconnected from the circuit board. After rereading the paragraph in the Dometic manual I realized that you are suposed to take the reading with the T/C connected to the board. When connected to the board it read 12.6mv.

Here is what I missed when I first read the paragraph:

"During normal gas operation, the thermocouple should
produce 25 to 35 millivolts when connected to the lower
circuit board."

[richj]

How did you determine your thermocouple was the problem when it tested good? I ask because I'm going through the same situation with a Dometic RM2353 with the exception that my fridge shuts off randomly - could be an hour, a day, etc. I pulled my thermocouple and it tested at about 27-28mV as well.

[762x51]

The thermocouple was the problem.
I replaced it with the MC Enterprises 2932052018 Thermocouple I bought off Amazon and now the system works fine.

[dougrainer]

The Universal kit is for a 2932770015. You had the 293277001. That may be your problem. Since the Thermocoupler is putting out the required millivolts, the only thing left is the module board is not processing that signal to leave the Gas Valve open. This is from Dino boards website and seems to state the universal board will not work in your application. Doug

Note: The Mirco P-711 will not work to replace the 3850415-013 board found in Universal Power Board kits
# 3308741.002 (2-way) and # 3308742.000 (3-way). These kits change the gas valve wiring and DC element wiring
(in 3-way refrigerators only). Our 3850415.01 board will work to replace the board in both 2-way and 3-way kit.

[762x51]

No joy in Mudville - :h

I replaced the orifice and the system still does the same thing - Lights, stays on for about 40 seconds then shuts off.

I had cleaned the burner, electrode, and thermocouple last week before ordering a replacement control module. Output from the thermocouple is within Dometic's spec.

Any other thoughts?

[wolfe10]

While you are in there, removed and clean the burner tube. Make sure the thermocouple is clean with no carbon deposit on it.

[762x51]

YC 1 wrote:
Turn off the gas and remove the tiny orofice from the tip. Soak in alcohol for an hour. DO NOT insert anything into the end. Not even a tooth pick.

A tiny piece of something can act like a flapper valve. Gas flows, flap closes.

Thanks for the tip and the orifice is soaking in alcohol now. I'll reinstall it in an hour and post the results.

[YC_1]

Turn off the gas and remove the tiny orofice from the tip. Soak in alcohol for an hour. DO NOT insert anything into the end. Not even a tooth pick.

A tiny piece of something can act like a flapper valve. Gas flows, flap closes.