Dometic CFX3 55im freezing

Hey folks! Our dometic will just freeze everything no matter the temperature we set it at. I have no idea where to start diagnosis on these and the internet has not been helpful thus far.

Any ideas or resources?

Did you get it from Amazon perchance?

Its the thermocouple / thermistor (temperature sensor). On the ARB you take off the access panel, unplug, pull out, put new one in and its fixed. (or you can read a post on MUD that makes it waaaaaaaay more complicated involving drilling, insulation shipping, soldering and spray foam to do the exact same thing)


View: https://youtu.be/O_jkQdf5onQ?si=mdYB5i5bmrP751oj

This is the correct looking sensor end.


Look to be two different plug end styles. Many more selling this one on Amazon:


For ARB challenge was finding the apart., but since Dometic is the mfg for ARB, maybe next time I'll try the easier to find Dometic part. Mine is acting funny and I replaced it a few years ago, so maybe I'll try one of these anyway or get a spare. Amazon search "dometic cfx3 55l thermistor" looks like the correct part. MAybe pull yours first for a visual. Happy to lend you a 75L while you fix yours.

$10 by Monday.

Other plug style:

It's interesting that the firmware wouldn't handle that as an error. All my 3D printers will recognize a faulty sensor, whether thermistor or thermocouple.

DanielChase said:

Did you get it from Amazon perchance?

Click to expand...

No it was an RV supplier iirc

Inukshuk said:

Its the thermocouple / thermistor (temperature sensor). On the ARB you take off the access panel, unplug, pull out, put new one in and its fixed. (or you can read a post on MUD that makes it waaaaaaaay more complicated involving drilling, insulation shipping, soldering and spray foam to do the exact same thing)


View: https://youtu.be/O_jkQdf5onQ?si=mdYB5i5bmrP751oj

This is the correct looking sensor end.


Look to be two different plug end styles. Many more selling this one on Amazon:


For ARB challenge was finding the apart., but since Dometic is the mfg for ARB, maybe next time I'll try the easier to find Dometic part. Mine is acting funny and I replaced it a few years ago, so maybe I'll try one of these anyway or get a spare. Amazon search "dometic cfx3 55l thermistor" looks like the correct part. MAybe pull yours first for a visual. Happy to lend you a 75L while you fix yours.

$10 by Monday.

https://www.amazon.com/TUELETFU-Refrigerator-Thermistor-Replacement-Replaces-3851210025/dp/B0B3QZ4NLD/ref=sr_1_17?crid=3OZD2IZX94V6W&dib=eyJ2IjoiMSJ9.uWlmY52kJ_-2_TrvPVaQIWwgT295Bt_FZRAN026xtvNqTZBIfqdcbG-i5AH6lu1DYjms81gluybtFGza2jNeB95nTY7X1MpHZfriVWS__J_hFcixAd7mPO28PuP-iWIEjqtSWS_h2-G4rY61gRyQTdap35qtGXPNn1g_5ZaZqTHnZXJBUQHbxtVBlHYIsbHgV1zS9mdML-Q99zVi4bO7IBPWwU5ZnbdSKldEti2Q0-BAsVNxi1Fpm0-_ktiaVGvIpKTXb9bu1PkFlvoOdoib-qe4J9tSFZXKLQQgu0HO21w.TBrX6bRdQBtrhf2jDrwI4qxuYQEcpoJpp1PEuXGnFgE&dib_tag=se&keywords=dometic+cfx3+55l+thermistor&qid=1790436668&sprefix=Dometic+CFX3+55l+thermistor+replacement%2Caps%2C248&sr=8-17

Other plug style:

Amazon.com: Replacement Thermistor Kit for Waeco CFX DZ Series - Short Thermistor - All CFX-DZ & CFX-DZW Series : Automotive

Amazon.com: Replacement Thermistor Kit for Waeco CFX DZ Series - Short Thermistor - All CFX-DZ & CFX-DZW Series : Automotive

www.amazon.com

Click to expand...

That makes sense. I’ll have to dig into it. I assume the error is the thermistor thinks it’s at 38 deg when actually lower.