AC won't turn back on

[pspc271]

So I just bought a brand new Sabre 5th wheel. The A\C is blowing nice and cold for a while then shuts off. As as the temp goes up inside the camper you'd expect the unit to kick back on but it won't. The only way I can get it to turn back on is if I set the thermostat to off, wait a few seconds, then go back to cool. Both the front and rear A/C units are doing the same thing. Any ideas?

[Chris Pastuzyn]

Welcome to the forum from New Jersey, Just got back from Delaware, Try taking the AC off auto, run on either low or hi, This should keep the fan running while the compressor cycles on/off.

[rockfordroo]

In my experience, you have a bad thermostat. If it's an analog, replace it with a digital (even if it's not bad).

[Bama Rambler]

If you have a Dometic single zone thermostat, you can try initializing it. That works sometimes, but other times it's as Roo said, the thermostat is defective.

[email]

This is a known issue with some dometic ac's.



It happens so often dometic does even require a repair sheet. They recommend installing their "repair it" which includes a new control box, thermostat, and for some odd reason new a/c mounting bolts.


Side note: If anyone has issues with their capacitive touch tstats, its the same thing, no questions asked, dometic will send you a new face plate for the tstat.

[Larry0071]

Maybe a related question.... Can the T-stat be set to fan only with no heat or ac?


Mine has 4 mode stops along the menu path. Hit the left MODE and it goes from OFF to FAN (Low/Auto/High), HEAT and COOL. It seems that I touch the mode button to select the fan mode, and that is selecting the fan mode for the heat or cool mode. It does not seem to have a stand alone fan to circulate air.


I really wish that the AC or furnace had a fan/vent to exhaust hot air out and pull cooler outside air in as the evening arrives. Am I missing something, or is that not an option on these systems?

[CincyGus]

Depends on the unit. Mine allows Fan, HI Cool, LOW Cool and HEAT.

[MIceman]

Originally Posted by pspc271

So I just bought a brand new Sabre 5th wheel. The A\C is blowing nice and cold for a while then shuts off. As as the temp goes up inside the camper you'd expect the unit to kick back on but it won't. The only way I can get it to turn back on is if I set the thermostat to off, wait a few seconds, then go back to cool. Both the front and rear A/C units are doing the same thing. Any ideas?

2021 Prime Time Crusader. This exact problem showed up during our first trip with the unit being less than a month old. It would cool down , shut off and then not come back on until I turned it off for at least 10 seconds. It would come on and then do it again. After talking to the Good Sam A/C tech, I ended up replacing the thermostat. It worked for three cycles and then back into the same scenario. Through a lot of trial and error I discovered that when you turn the power off, as I did when I replaced the thermostat, the 3 cycle thing would occur then back to one cycle and off. That was back in 2021. I took it to Camping World, where we bought it, and their report was “works as designed”. In other words they couldn’t duplicate it. Now we are back in the camper for a while it was working fine but the problem showed up again. I’m thinking it’s an issue in the control box inside the roof top unit but try to get a prompt service appointment, especially when you are living in the camper full time, is impossible.