Digital Thermostat in Series with Dometic Thermostat

[peteco]

For you thermostat wiring gurus I have a question. Is there a way to wire a new digital thermostat in series with the Dometic thermostat. The new thermostat would control the on and off temperature, because the Dometic does a very poor job of that with large temperature swings. I would also locate the new thermostat not on the outer wall to prevent solar wall heating from affecting the thermostat. I ask this because my understanding is the Dometic CoolCat thermostat wiring sounds a bit tricky, so using the new thermostat to provide power to the Dometic thermostat would be work-around. Does this concept make sense, or is there a better way to get around the Dometic thermostat issues?

 

[hbn7hj]

One person claimed she had it done without removing the unit. She never answered the questions so I doubt it happened.

The only way I know to put a digital thermostat on an old Cool Cat is to replace it with a new one, which I did. You can intercept the two wires from the furnace and port them to an aftermarket battery powered thermostat. Mounting the thermostat on a 1/2” piece of foam helps the solar problem. I don’t know how to add a digital control to the A/C part.

The analog thermostat has 10 degree hysteris which is the problem.

 

[GaryG-ClassB]

I think the issues with Dometics and fluctuation temperatures isn't so much the lack of a super accurate thermostat or it's position in the fridge. It's that the evaporative cooling process is so slow compared to a compressor fridge and they are far more effected by the ambient (outside) temperature. I improved the situation on mine by adding a manual switch to the outside coil fans. If your fridge doesn't have outside coil fans, there is a kit available. Here is a thread I started on the subject a couple of months ago. Hope this helps: https://www.classbforum.com/forums/f8/trick-to-make-sprinter-roadtrek-fridge-work-better-12785.html

 

[GaryG-ClassB]

Also, I bought a super cheap ($5) electronic thermometer with a probe on a 3 foot wire. The unit is attached with velcro to the wall above the fridge and the probe simply goes into the fridge via the front door. Although it doesn't control temperature, it gives a very accurate temperature of the interior.

 

[ChicagoTom]

Sorry, but I think it's best to KISS. I still don't understand why everything has to be so complicated. Full timed and was just fine with all the stock appliances etc. Now I'll get ready to be blasted! LOL

 

[themexicandoctor]

Chicago Tom you are 1. The recipient of individually the best made Dometic RM unit in the USA 2. It's also your field 3. I agree, KISS is best 4. Many of the Gurus on here though, to our benefit are over achievers & like to squeeze the the very last performance from our systems - in many areas of life, I am the same 5. There seems to be a disconnect (not on your part) as here someone is talking about the Thermostat in a Cool Cat AC Unit & another, a Thermostat in a Dometic Fridge. Or maybe I have misread it.

 

[GaryG-ClassB]

Yep. My bad. Thought he was talking about a fridge.

 

[themexicandoctor]

Yep. My bad. Thought he was talking about a fridge.

I thought he was talking about my fourth ex wife ...