A/C continues to operate after passing the temperature setpoint at the thermostat

[Imagine_Nation]

We are going through the extreme hot spell here in Central Oregon and experiencing triple digit temperatures. We had decided to sleep in the RV (2021 Imagine 2600RB) last night. The inside temp was 99⁰ F when we opened up the rig so I started the A/C on "High Cool". Assuming that I could only gain about 20⁰ F of cooling from an ambient of 99⁰ F, I set the thermostat to 80⁰ F. It took awhile, but it finally got down around 80⁰. It stayed there until outside temperatures began to fall and then the inside of the RV went below 80⁰. 80⁰ was my setpoint, but the A/C never shut off. I woke up in the middle of the night and we were at 73⁰ with the A/C still running, which was nice and comfortable, but my concern was that the A/C setpoints were not working. Anyone else experienced this?

[Country Campers]

Imagine_Nation

What brand of A/C do you have? Model?

Brian

[acoleman43]

Look at the thermostat. If it shows "auto" it will stop at the designated temperature. If it just show AC Hi or AC low, it will keep running until you turn it off.

[Imagine_Nation]

Hey Brian:

Thanks for the response. We have the Coleman Mach with the Airxcel thermostat. It does show just the "Cool Hi" display, so I guess ours won't cycle around the setpoint? Do you think that is a function of the thermostat? I have seen our same model with a more expensive looking thermostat.


Again, appreciate the help.

Guy

[Jlawles2]

Our thermostat cycles from ON to Auto. Try pressing the mode button an looking for the AUTO to illuminate with the HI and LOW.

I believe ours cycles FAN LO - FAN HIGH - COOL LOW - COOL HIGH - COOL AUTO LOW - COOL AUTO HIGH - HEAT - OFF

[acoleman43]

Our thermostat cycles from ON to Auto. Try pressing the mode button an looking for the AUTO to illuminate with the HI and LOW.

I believe ours cycles FAN LO - FAN HIGH - COOL LOW - COOL HIGH - COOL AUTO LOW - COOL AUTO HIGH - HEAT - OFF

Exactly. Keep pressing the rectangle button until it shows Auto. It will cylce through a bunch of options before you get to high auto

[Imagine_Nation]

Hello Joseph and all:

That was it. I just needed to scroll further to the Cool High or Cool Low "Auto" setting.

Back in business!

[Lonestar]

Look at the thermostat. If it shows "auto" it will stop at the designated temperature. If it just show AC Hi or AC low, it will keep running until you turn it off.

I believe "Auto" refers to the fan operation, not the compressor. If in "Auto" the fan cycles on/off with the compressor. Even if the fan continues to run in the "cool high or cool low" setting the temp should not keep falling. The compressor should turn off and maintain the designated temp.

[acoleman43]

I believe "Auto" refers to the fan operation, not the compressor. If in "Auto" the fan cycles on/off with the compressor. Even if the fan continues to run in the "cool high or cool low" setting the temp should not keep falling. The compressor should turn off and maintain the designated temp.

That's how I thought it worked as well in the beginning. It took me a bit to figure it out.....there is a fan only mode (I believe high and low), an AC high/low mode, and AC Auto High/low mode, a heat mode and off.

[Jlawles2]

We have found that leaving the fans on LOW at night (with the 2 units) helps to even out the temps in the camper along with not waking us due to the cycling of the fans.

You are correct that the compressor will cycle off and on based on set temp. Similar to the way a home unit would work if you flipped the fan to ON vs AUTO.

[Lonestar]

We have found that leaving the fans on LOW at night (with the 2 units) helps to even out the temps in the camper along with not waking us due to the cycling of the fans.

You are correct that the compressor will cycle off and on based on set temp. Similar to the way a home unit would work if you flipped the fan to ON vs AUTO.

Since I usually only have to run the living area A/C, I leave the fan on low or high for the same reason as you. I just don't like to listen to it cycle on and off plus it circulates the cool air through the trailer when the compressor is off. In fact I do the same in my house.

In real hot weather, if an A/C coil tends to freeze up, the fan running continuously will usually prevent this from happening.

In the OP, I'm still not sure I understand why the temp continued to go below the set point when on High Cool. Regardless of the fan setting the compressor should not continue to run.

[Jrnjulie04]

We experienced this the past weekend on our first trip out with our 2023 2600RB. We set it for 74 and it ran until it was at 63. Very cold at night for us! It is set on “Dry” for air conditioning so that the fan runs and the air conditioner cycles off and on as needed. Can’t find a way to override it from getting so cold and not stopping at 74.