Dometic 2652 won't stay lit on LPG

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AK_RVer

New member
Joined
Jul 21, 2018
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2
I have a fairly new (2016) Dometic 2-way fridge (no DC), model 2652, that runs great on shore power.  When not on shore power, it "clicks and lights" instantly, about 20 seconds after turning on the fridge at the control panel. The flame is big and bright, centered directly under the flue, and the electrode tip is directly in the flame glowing nice and orange.

However, after about 30 seconds of flame, it "attempts to ignite again"(???). (my term - I'm not exactly sure what it's doing)  Essentially, it starts going click-click-click for about 30 seconds. Then everything stops. No more clicking, no more flame.  After about 2 minutes, this entire cycle repeats: 1 click and the flame lights, 30 seconds elapses, then it clicks for 30 seconds, then everything turns off. 

This whole process can go on for hours, if I let it.  Meanwhile, the fridge is not cooling and the "Check" light on the control panel will never come on.


I'm new to this whole thing, so my few hours of Google Foo has led me to believe that this might be:
A: the "flame sensor" is not detecting a flame, and so it shuts off to attempt again later
b: the "thermocouple" is not detecting any heat, and so it shuts off to attempt again later

Does anyone know any other possible options?  And, as a follow-up, what and where are the "flame sensors" and the "thermocouple", and how could I troubleshoot these two parts?


Thanks! 

Jim
 

grashley

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May 7, 2015
Posts
6,586
Location
Western Kentucky
Welcome to the Forum!

The flame sensor and thermocouple are the same thing.  Yes, a faulty or out of position thermocouple could cause this.  Yours is NOT out of position.  They are inexpensive and easy to replace.  Any big box store (Lowes, Home Depot, Ace, True Value) should stock them.  it is not an RV specific part.

One other possibility is the signal from the thermocouple is not getting to the control module due to corrosion and a poor connection.  Unplug the thermocouple and clean the connection as best you can.  Pencil erasers work well.  Then plug - unplug a dozen times to try to increase clean contact area, then try the fridge again.  Try this first - it is free!
 

lungesport

Member
Joined
Nov 12, 2017
Posts
20
Location
SF Bay Area
Here?s another possibility...
The gas burner flue could be the occluded with debris.
I had a similar situation while boondocking and found a long blade of fairly stiff grass to run up the tube that vents the burner.
I now run a long brush into the vent a few times a year as a precaution.
 

AK_RVer

New member
Joined
Jul 21, 2018
Posts
2
Thanks for the replies!

@darsben, yes all other appliances work great on gas.

@grashley, Thanks for the clarification re: "flame sensor" vs "thermocouple".  So, now I guess my next question is... which part is it, and is it simple to remove?  I assume it's the little white ceramic-looking thing with a metal tip that is sticking into the flame?  This has a long wire that goes into a cluster of other wires, so I'll need to pick that all apart and unplug it from the control board, I guess.

I have the following diagram, but no mention of a part labeled "thermocouple".  The part that (I'm assuming) I'm after is labeled an "Electrode with conductor" in this diagram.

https://s22.postimg.cc/g5m27of5t/screenshot_68.png

https://s22.postimg.cc/nycpzkl41/screenshot_67.png
 

muskoka guy

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Joined
Oct 15, 2012
Posts
1,114
Location
MUSKOKA ONTARIO
Check the voltages of all your batteries. I have seen trouble with gas fridges and water heaters that were caused by low voltage from the batteries. This is probably not the problem, but I have seen it be the problem several times.
 
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