Dometic Fridge Thermistor Replacement

We have been noticing of late that our fridge does not seem to keep things as cool as we think it used to. A few factors could be related to this, such as the really hot summers we now have, and of course, the age of the cooling system. A little research pointed me in the direction of replacing the thermistor, which controls the preset temperature, as a simple and relatively inexpensive first action to see if there is an improvement.



A quick search on Amazon turned up the correct part, and a tip for Canadian owners, try to source it on Amazon.com, as you will find the prices significantly cheaper. Of course, you then have to figure out how to get it, and we have found shipping it to a UPS store somewhere along your travels is a good option.

RM2351

The hardest part of the installation is getting the cover off the control box. The way the fridge is installed, the cover is jammed tight against a metal channel, and this does not allow enough room for the cover to be maneuvered off. A few summers back I wanted to check the fuses found in that box, and had a hell of a time figuring out how to get this thing off. As chronicled here, http://routealto80.blogspot.com/2017/06/2-way-fridge-switch-over-issue.html , I think this is the only way to go about it, without pulling the whole unit forward from the inside, an even bigger effort!

Get the cover off, then disconnect the wire connector from the circuit board. Of course, there was a little zip tie preventing the complete removal of the wire without cutting the connector off. As I wanted to keep the old thermistor intact, I worked at getting some small side cutters around the tie. Then I went inside and removed the thermistor holder from the refridgerator fins, removed the thermistor, then the little plug for the hole. After that it was just a matter of reversing all the tasks, a few zip ties to clean things up, cover back on, and you are done.

The fridge fired up no problem, and although it is only the first time out, the internal thermometer is showing that the fridge does seem to be cooling thing off a little further. One other think I noticed was the impact of the placement of any thermometer used to monitor the internal temp of the fridge. We use a wireless temp sensor, and I originally had this placed in the back left corner of the interior. This I found resulted in a higher temp reading, to the tune of 3-4F, than when it was moved, as a test, to the middle of the lower shelf. This sort of makes sense, as the back wall of the fridge is the closest to not only to the workings of the fridge, but also an increase caused by the sun pounding on the sidewall. Given that an absorption fridge works using heat as part of the process, it is little wonder that the back of the fridge might be a tad warmer.

So in short, I think changing the thermistor, and finding the best location for getting an accurate temp reading, were good moves.
Win Win.