AC Thermostat and Short Cycle.

[Gobirds38]

Has anyone replaced the thermostat with a house thermostat?

On our recent trip, I wanted to just run the fan only, the Dometic one doesn't offer that function.

Also noticed the AC short cycle when ran on auto fan, after noticing the fan running on low it would short cycle. I then set it to run on high fan speed and no problems.

[sourdough]

What thermostat do you have? Is it the capacitive touch one? If so it has a setting for "high" fan mode (just double checked on mine) and that is what it does.

As far as replacing with a home thermostat, which is what I considered, Dometic told me the thermostat had to work with the controller in the AC and the Dometic unit was the only option.

[flybouy]

Home thermostats typically operate from a transformer that takes the 120 vac and steps it down to 48 v ac (the same transformers are often used for wired doorbells. The camper uses the 12 vdc from the battery/converter to operate the thermostat and 120 vac relay in the air conditioner.

[Gobirds38]

Originally Posted by flybouy

Home thermostats typically operate from a transformer that takes the 120 vac and steps it down to 48 v ac (the same transformers are often used for wired doorbells. The camper uses the 12 vdc from the battery/converter to operate the thermostat and 120 vac relay in the air conditioner.

Thanks, I will just have to make mine work.

[wobly]

I did use a home thermostat in our previous trailer. It was battery operated off of two AA batteries. I bought it at Walmart. You could have the fan on, but it only ran on high. But, with a lot of the modern systems, I don't know if they would even connect up.

[flybouy]

Originally Posted by wobly

I did use a home thermostat in our previous trailer. It was battery operated off of two AA batteries. I bought it at Walmart. You could have the fan on, but it only ran on high. But, with a lot of the modern systems, I don't know if they would even connect up.

Some folks have done that with the older thermostats and to get both fan speeds requires adding a separate fan switch. There are some posts with that mode here somewhere.

[meaz93*]

I have to tell you that I changed both Coleman-Mach's out with Honeywell Focus Pro 5000's....and they work perfect. Set AC on auto and the AC ran to temp than shut off....when it dropped to 54° in the morning the heat kicked on without having to manually set!
One of the best upgrades for my Outback.

[skids]

Originally Posted by meaz93*

I have to tell you that I changed both Coleman-Mach's out with Honeywell Focus Pro 5000's....and they work perfect. Set AC on auto and the AC ran to temp than shut off....when it dropped to 54° in the morning the heat kicked on without having to manually set!
One of the best upgrades for my Outback.Attachment 28224Attachment 28225

I may consider that change. I went out to the camper last night to check things out after torrential hail and rain. The air conditioner clicked on when I walked past the thermostat and the AC came on. I tried to adjust temperatures and it was apparently in Celsius mode Rather than Fahrenheit. So I drug out the manual and resetting it according to directions was very “futzy.” I finally was able to do it before turning off the system.

[MSB1766]

Here is the digital thermostat that replaced the factory with, works great:
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

[sourdough]

Just as a reference, I believe the OP has a new 2020 trailer with a Dometic thermostat (capacitive touch I assume). As far as I know the Coleman thermostats are not interchangeable with the Dometic nor are any aftermarket units per Dometic. The main thing is I assume it is in warranty and replacing with any of those would probably void the warranty. On what? Who knows if the AC malfunctioned and went belly up that might be on the OP for not using OE equip.

[meaz93*]

Obviously the OP's 2020 TT has a basic 1yr warranty and I personally would not change out anything that would jeopardize that. My Outback is a 2018....so it was a very easy choice to upgrade myself.