AC Thermostat Control Problem

[RParker]

Our 2018 Montana has 2 AC's (one is also a heat pump) when set at 72 degrees for example it will cool to the set temperature (Dometic thermostat) but won't turn on again until the temperature is 75-78 degrees. When heating both thermostats control the gas furnace or heat pump just fine heating as expected (like in a home).

The trailer was at the dealer in for 3 weeks August and they couldn't duplicate the problem. I provided several videos showing the set temperature (72 degrees) with another digital thermometer within a few inches reading 75+ degrees. Also showed (via video) scrolling through the Dometic thermostat functions showing it was also reading 75+ degrees.

The dealer would only say this is normal, but we've had 2 motorhomes and another trailer previously and I know this isn't "normal".


Any ideas?

[DQDick]

Call Dometic. They have replaced the thermostats for several folks based on what they were doing.

[AZ Traveler]

RParker,

The thermostats are not vey accurate. A 4-6 degree error is not uncommon.