Dometic 4223, propane won't stay lit

buildintechie

Member
Jul 12, 2014
38
Hey all-
The first couple times I camped with my new to me popup, the fridge worked great on propane. Was told when I bought it that 120 didn't work on it. Lately, I'm able to get the ignition to strike, and I get a good blue flame, but it won't stay on if I don't hold down the button on the propane controls.

Yesterday, I started looking at it, and determined the 120v element is fried...tested it and only get 80 ohms of resistance, when it should be higher than that (don't recall how much off the top of my head). A replacement element is awfully expensive, I'd rather get it fixed on propane and not worry about it as something to invest in right now.

So, on the propane side, like it said, it DID work very well. I get a good blue flame when I start it, and even if I hold the button down for 5 minutes, it still goes out when I release it. My plan is to pull the fridge tomorrow, and clean out the flue and the "crack pipe". I'll follow the instructions in the Sticky "SUCCESS! Propane Fridge Repair". Any other suggestions people might have for me? How can I test the thermocouple, and make sure it still works? I know it should be giving out 30ish millivolts, but where should i measure that from (or can I)?

I appreciate your thoughts and suggestions!

Thanks!
 

Phranc

Active Member
Apr 9, 2014
683
Take a piece of fine steel wool and polish the thermocouple. Make sure it's centered in the flame. Search on the manufacture's website for your model and look at the literature for your model of the thermocouple placement. It should be centered in the flame and less than 1" above, or it may be required to be in the flame.
 

buildintechie

Member
Jul 12, 2014
38
The burner assembly actually has a housing with a detent that the thermocouple sits in, ensuring its positioned properly. It is in the flame...I cleaned it with some steel wool...still no luck.

I can't seem to figure out how to remove the thermocouple from the valve assembly...its tight against the back of the fridge, and I can't remove the propane control assembly bracket, because the ammonia piping is blocking one of the screws.

See the picture in the next post.
 

buildintechie

Member
Jul 12, 2014
38
The whole shebang:
1c915c361daa27456f879e2c1d7d0551.jpg


Burner assembly, partially removed:
94a11b001b1096bf9dcab5b94ac5ec00.jpg


Black "wire" is the thermocouple.
5e0fcf241edcf69af4758c01c22f96fd.jpg


I can only see 1 screw...
595359abf2beca56265e58b61b7a0534.jpg



Sent from my iPhone using Tapatalk
 

buildintechie

Member
Jul 12, 2014
38
I replaced the thermocouple, and the fridge works now!

I found a 99.9999% exact replacement at Carolane...a NC based propane/grilling store...for only $15.00
 




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