Thread Tools Display Modes
Old 08-31-2016, 07:30 PM   #1
Senior Member
KDHfan's Avatar
Join Date: Feb 2013
Posts: 848
Dometic A/C issue

Camping over the weekend and had an issue with our Dometic A/C unit. Temps were in the mid 90's, no clouds. We were parked in full sun... So needless to say, it was hot.
We had the a/c running with the fan on continuous "Hi" for a while to get the inside temp down to where we wanted it. I then switched it over to "auto" so that it would shut off when it reached desired temperature.
The problem: When the desired temp was reached, the fan would shut off (because it's on auto), but the compressor continued to run. It would run for about 3-seconds, then the fan would kick back on. I tried everything on the thermostat, but nothing would fix it. Finally, after the sun went down, it started working properly. It did this on two consecutive days.
Anyone know what would cause this?
Coachmen Apex 288BHS. 13,5k AC.

2015 Coachmen Apex 288BHS
2014 Toyota Tundra CrewMax 5.7L
KDHfan is offline   Reply With Quote
Old 08-31-2016, 07:41 PM   #2
Junior Member
Join Date: Jul 2015
Posts: 20
Yep we did,on a brand new unit,I had service come and look at it,they replaced control panel and thermostat . It worked for a few weeks with no problems,then same old stuff, they don't know what the problem is, still working on a fix..

danny296 is offline   Reply With Quote
Old 08-31-2016, 07:43 PM   #3
Senior Member
Bluepill's Avatar
Join Date: Jun 2015
Location: Pensacola, FL
Posts: 533
It *may* be "normal" operation. My 10K BTU Dometic "CoolCat" heatpump/AC often does the same thing. My best guess is that the fan shut down period is used to give the thermostat a chance to detect temperature with no air moving around it. The cycle will repeat from time to time, and eventually the fan speed will switch back to low rather than high. This is usually in the evening when the heat load is becoming less.

It's also possible that it is a microprocessor program fault. My unit is past warranty, so I am not going to bother with it, since the overall operation is fine.

You can reboot the thermostat microprocessor by disconnecting the 12 volt battery for 15 minutes when you have no shore power connected.
2015 T12RBST Flagstaff Hardside
2008 Itasca Meridian 37H
Bluepill is online now   Reply With Quote
Old 09-01-2016, 10:19 AM   #4
Head Rambler
Join Date: Mar 2008
Location: Southwest Alabama
Posts: 3,309
Mine did it once, but hasn't done it again. There have been reports of it happening because the wall behind the thermostat wasn't insulated and it allowed hot air to continually trigger the t-stat after the fan shut down. Insulating behind the t-stat and/or adding some type stand-off mount to it seemed to fix the problem.

I assume you also have the LCD thermostat. If so, you can initialize it and see if that helps.
Salem 29RKSS Pushing a 2500 Mega-Cab CTD!
Gotta go campin!
Bama Rambler is offline   Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

» Virginia Campgrounds

Reviews provided by is not in any way associated with Forest River, Inc. or its associated RV manufacturing divisions.

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 05:41 PM.