New Dometic 3 button thermostat shuts down AC system at will

Vulcan Rider wrote:

MM49 wrote:
It could be condenser freezing also. I notices mine is dumping a lot of water during this cycle.
MM49

It is also possible that it has a "high water" float in the collection tray that will shut it off if the drain hose is plugged or otherwise not draining fast enough.

MM49 wrote:
It could be condenser freezing also. I notices mine is dumping a lot of water during this cycle.
MM49

RobertL0 wrote:
Thanks, but I am able restart the unit immediately by shutting it off, then on, via the thermostat..I think high head pressure would prevent me from starting the compressor immediately

MM49 wrote:

RobertL0 wrote:


For me to restart the cooling, I need to shut off the AC via the thermostat, and then turn it back on. The problem will the repeat itself.

I would rather do the work here, then leaving the RV at a service center for a few days if I can, especially in the mid of summer camping.

Think replacing the thermostat will do the trick? Are there better thermostats out there than the Dometic?

Thanks in advance

Your problem is real. I have a new Sunny Brook with the same issues. It seems like it is cutting out from high head pressure. It resumes later. This only happens in very hot weather.
MM49

MM49 wrote:

RobertL0 wrote:


For me to restart the cooling, I need to shut off the AC via the thermostat, and then turn it back on. The problem will the repeat itself.

I would rather do the work here, then leaving the RV at a service center for a few days if I can, especially in the mid of summer camping.

Think replacing the thermostat will do the trick? Are there better thermostats out there than the Dometic?

Thanks in advance

Your problem is real. I have a new Sunny Brook with the same issues. It seems like it is cutting out from high head pressure. It resumes later. This only happens in very hot weather.
MM49

RobertL0 wrote:
We have a 2015 Coachman with the Dometic 3 button thermostat, running their 15K BTU unit.
When in AC mode, (fan speed set to low or high), the RV will get to it's set point, then the compressor AND the fan will shut down at the same time. I'm NOT talking about having the fan speed on auto.

There are no temperature sensors in the RV , other than the one on the thermostat.

For me to restart the cooling, I need to shut off the AC via the thermostat, and then turn it back on. The problem will the repeat itself.

I would rather do the work here, then leaving the RV at a service center for a few days if I can, especially in the mid of summer camping.

Think replacing the thermostat will do the trick? Are there better thermostats out there than the Dometic?

Thanks in advance

dougrainer wrote:
I am not assuming they are all alike, I listed the Med, because some do have medium. But the systems all function the same in regards to your complaint. I have 36 years as an RV tech and am Master Certified.

lenr wrote:
Our newly installed tstat and control board now seem to be not starting up on auto fan. Had it set to 62 with the tstat saying it was 77 with no start. Finally took off and ran after several cycles of the push button thru tell heat-off-fan speed-a/c positions. Can't find a tech support number for Domestic--they only talk to dealers. I don't believe this is a dead band issue. If the dead band is this wide, then this tstat is total junk. The manual says it will switch to high fan when 5 degrees from set point--it does not say there is a 5 degree dead band.

lenr wrote:
Domestic had a bunch of bad control boards a few years ago. We just had the thermostat and control board replaced on our digital control 15K a/c system and it solved a few screwy problems. Temperature control is still terrible. Stat is very slow to react. You cannot change to any other stat without rewrite of the control because this one uses only 3 wires including furnace control. The switching between low and high fan uses control signals on one wire which causes the pause between fan speeds. Low on our15K doesn't seem to have much cooling capacity and you only get high when there is 4 to 5 degrees from set point. We end up forcing the fan to continuous high and letting the compressor cycle to get compfortable. Seems like a junk design to me--probably saved someone a $1.95. My son just got a Coachman TT with a Coleman a/c and a manual mechanical thermostat. Kind of wish I had the same!