AC short cycling.

**pappcam** · 06-02-2023, 10:05 AM

Dometic 15k AC and Dometic soft touch thermostat short cycles my AC. It comes for about a mimute and then shuts off in about a minute and repeats this. Seems specific to when the temp outside is close to the temp inside. Sometimes it's the fan only and I don't hear the compressor kick in before it shuts off again.

There is no vent pointing at the thermostat so it's not that. Hell, I'm not even sure the thermostat has the temperature sensor in it.

It's very annoying.

I'd also like to repeat how brutal this site is on mobile.

**Soundsailor** · 06-02-2023, 10:38 AM

Originally Posted by pappcam

Dometic 15k AC and Dometic soft touch thermostat short cycles my AC. It comes for about a mimute and then shuts off in about a minute and repeats this. Seems specific to when the temp outside is close to the temp inside. Sometimes it's the fan only and I don't hear the compressor kick in before it shuts off again.

There is no vent pointing at the thermostat so it's not that. Hell, I'm not even sure the thermostat has the temperature sensor in it.

It's very annoying.

I'd also like to repeat how brutal this site is on mobile.

There have been a few threads here on the short-cycle issue. Some have found moving the sensor helps.

As far as displaying the site on mobile, my phone (Android) uses the Google Chrome browser. It has the option to display the desktop version of the site. Since that results in pretty small type, I'll often turn the phone on its side to get a horizontal display which allows me to zoom in a bit.

**pappcam** · 06-02-2023, 10:46 AM

Originally Posted by Soundsailor

There have been a few threads here on the short-cycle issue. Some have found moving the sensor helps.

As far as displaying the site on mobile, my phone (Android) uses the Google Chrome browser. It has the option to display the desktop version of the site. Since that results in pretty small type, I'll often turn the phone on its side to get a horizontal display which allows me to zoom in a bit.

Where is the temperature sensor? I assume not in the thermostat? That's where I thought it would be but that POS thermostat doesn't have much going on.

**Soundsailor** · 06-02-2023, 10:51 AM

Originally Posted by pappcam

Where is the temperature sensor? I assume not in the thermostat? That's where I thought it would be but that POS thermostat doesn't have much going on.

In some AC units it is in the unit itself. Not surprising that it signals cold too soon. This link might help: https://www.google.com/search?q=gran...&ie=UTF-8#ip=1

**Soundsailor** · 06-02-2023, 10:53 AM

This (https://www.google.com/search?q=gran...t=gws-wiz-serp) link might be better.

**pappcam** · 06-02-2023, 12:21 PM

As a somewhat related question to my Dometic AC issues, where can I get the app that can control my HVAC through Bluetooth? My t-stat is a Bluetooth enabled unit as the Bluetooth symbol is on it and I can see the symbol flashing. Apparently the app is called Dometic CT or CTBT but it's nowhere to be found.

**xrated** · 06-02-2023, 12:49 PM

Originally Posted by pappcam

Dometic 15k AC and Dometic soft touch thermostat short cycles my AC. It comes for about a mimute and then shuts off in about a minute and repeats this. Seems specific to when the temp outside is close to the temp inside. Sometimes it's the fan only and I don't hear the compressor kick in before it shuts off again.

There is no vent pointing at the thermostat so it's not that. Hell, I'm not even sure the thermostat has the temperature sensor in it.

It's very annoying.

I'd also like to repeat how brutal this site is on mobile.

Sometimes, short cycling can also be an indicator of lack of refrigerant in the system, and if that is the case, your unit has a refrigerant leak. Is this something that just started happening, or has it been doing this for some time? You might want to go up on the roof and pull the A/C shroud/cover off of the unit and look around at the refrigeration lines, the compressor itself, the evap and condensor coils.....anything and everything that is in the refrigeration loop. If you see an oily looking spot, it's probably a sign that there is a leak, since there is refrigerant oil in the system also.

**pappcam** · 06-02-2023, 01:33 PM

Originally Posted by xrated

Sometimes, short cycling can also be an indicator of lack of refrigerant in the system, and if that is the case, your unit has a refrigerant leak. Is this something that just started happening, or has it been doing this for some time? You might want to go up on the roof and pull the A/C shroud/cover off of the unit and look around at the refrigeration lines, the compressor itself, the evap and condensor coils.....anything and everything that is in the refrigeration loop. If you see an oily looking spot, it's probably a sign that there is a leak, since there is refrigerant oil in the system also.

It's our first real trip out with the new trailer so it's the first time using it other than for a couple of minutes at the dealer walkthrough to make sure it worked.

It cools fine up to the point where it starts to short cycle.

**xrated** · 06-02-2023, 02:33 PM

Originally Posted by pappcam

It's our first real trip out with the new trailer so it's the first time using it other than for a couple of minutes at the dealer walkthrough to make sure it worked.

It cools fine up to the point where it starts to short cycle.

99.9% sure then it's not a refrigerant leak....that's good news because they are not made to be repaired and recharged. It can be done of course, but ....Anyway, it's not that.

One thing that kind of stands out to me, that you mentioned is that it seems to run fine, but starts acting up and short cycling when the outside temperatures are close to the inside temps. In those instances, it's pretty easy for the evaporator to freeze up...or at least the freeze sensor to take the unit off line, then back on...like what yours is doing. One of the solutions for that is to make sure that the fan speed is on high.....more airflow across the evaporator. Something you may want to look at too is while it is running normally (no short cycling yet), as soon as it starts the short cycling, be ready to pull off the inside cover and look to see if the evap is starting to freeze up. Also, you need to make sure that the freeze sensor in the evap coil is placed where it is suppose to be and definitely not just hanging by the wires. They normally are clipped to the fins on the evap. coil, but I don't know where Dometic places theirs exactly.

**Hoopy Frood** · 06-02-2023, 02:43 PM

Originally Posted by xrated

99.9% sure then it's not a refrigerant leak....that's good news because they are not made to be repaired and recharged. It can be done of course, but ....Anyway, it's not that.
...

Seriously, the AC units are basically disposable?