Living room ac stops starts right back up

jmarnell

Well-known member
Is there a problem with it freezing up ? After reading posts I guess this is normal

Our AC does that when the fan is switching from high to low speed, or low to high. When our Mobile RV repair guy was servicing our unit he said that's perfectly normal if you have the fan set on Auto.
 

cashmore

Active Member
On our Cyclone we were having an issue with the main area (middle) AC coming on and then going off over and over again most of the time not even running long enough to start the compressor. What we found was that behind the tstat for that area there was a rather large hole that the tstat wires were running through. When the front (bedroom) ac was on or the garage ac was on the air would come through the inside of the wall through that hole directly into the tstat which we assumed was turning off the main ac. So we covered that hole with a piece tape and reinstalled the tstat to the wall and it fix the issue for us.
 

JohnD

Moved on to the next thing...
Is there a problem with it freezing up ? After reading posts I guess this is normal

Our AC does that when the fan is switching from high to low speed, or low to high. When our Mobile RV repair guy was servicing our unit he said that's perfectly normal if you have the fan set on Auto.

It will do that because 'AUTO' fan mode is for the furnace...not the AC.

Run the AC unit on 'HI' or 'LOW' fan settings and it should work normally.
 

cashmore

Active Member
Assuming you have a Dometic AC and not another brand, there is no mention of running in hi or low mode and not using auto when using cool mode in the manual, in the manual it states:

In Cool Mode, the system cycles the compressor On and Off based on room air temperature and temperature set-point on the CT thermostat. The fan turns on first, followed by the compressor approximately 2 minutes later. There are three fan speeds in Cool Mode:
● “Low”: Fan operates continuously at low speed. The compressor cycles On and Off.
● “High”: Fan operates continuously at high speed. The compressor cycles On and Off.
● “Auto”: Fan speed varies depending on the difference between the temperature set-point and room air temperature. The compressor and the fan cycle On and Off with the CT thermostat.

Setting The Fan Speed (Fan Mode)

Fan mode provides three speed settings:
● Low – Fan operates continuously at a low speed.
● High – Fan operates continuously at a high speed.
● Auto – Fan and compressor cycle on and off and the speed varies based on room temperature and temperature setting on the CT thermostat. When the temperature difference betweenthe room and the CT thermostat is:
● >5 °F (-15 °C), the fan operates at a high speed
● <4 °F (-15.5 °C), the fan operates at low speed

The manual for this and other thermostats are available on the Dometic website https://www.dometic.com/en-us/us/pr...thermostat-control-kit-_-164516#documentation

Is there something that i'm missing? I run mine in Auto all the time on all 3 AC's and they all function exactly as the manufacture describe in the manual.
 

jmarnell

Well-known member
Assuming you have a Dometic AC and not another brand, there is no mention of running in hi or low mode and not using auto when using cool mode in the manual, in the manual it states:

In Cool Mode, the system cycles the compressor On and Off based on room air temperature and temperature set-point on the CT thermostat. The fan turns on first, followed by the compressor approximately 2 minutes later. There are three fan speeds in Cool Mode:
● “Low”: Fan operates continuously at low speed. The compressor cycles On and Off.
● “High”: Fan operates continuously at high speed. The compressor cycles On and Off.
● “Auto”: Fan speed varies depending on the difference between the temperature set-point and room air temperature. The compressor and the fan cycle On and Off with the CT thermostat.

Setting The Fan Speed (Fan Mode)

Fan mode provides three speed settings:
● Low – Fan operates continuously at a low speed.
● High – Fan operates continuously at a high speed.
● Auto – Fan and compressor cycle on and off and the speed varies based on room temperature and temperature setting on the CT thermostat. When the temperature difference betweenthe room and the CT thermostat is:
● >5 °F (-15 °C), the fan operates at a high speed
● <4 °F (-15.5 °C), the fan operates at low speed

The manual for this and other thermostats are available on the Dometic website https://www.dometic.com/en-us/us/pr...thermostat-control-kit-_-164516#documentation

Is there something that i'm missing? I run mine in Auto all the time on all 3 AC's and they all function exactly as the manufacture describe in the manual.

What you pulled from the manual is exactly what I was describing and our RV tech explained. We always run our AC's with the fan set to Auto, and the speed varies high or low to match the cooling need. We don't like the fan continuously running, especially at night when the cooling need is less. We prefer the quiet when the AC compressor shuts down. Just a matter of preference. Some folks may prefer the fan to run continuously.
 

cashmore

Active Member
We like to be in places where we don't need the AC which by default, solves the fan issue. However sometimes you just can't make that happen.
 

JohnD

Moved on to the next thing...
However, switching his AC from 'AUTO' to 'HI' or 'LOW' did solve his problem... :confused:

:cool:
 

Flick

Well-known member
Rodger that! Thanks

Well, there you go, a whole week of discussion and we’re right back where we started. Half do the auto thing and half do the hi-lo thing. I guess if your unit cuts on and off, do the hi-lo thing. If you don’t want the fan noise, do the auto thing if your ac allows it.
Personally, we don’t like the fan noise either but our unit only works well on hi-lo. So that’s what we use on these hot 105 degree days like today. Go figure. Lol.
 
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