BAC Forum

General Boards => General Discussion => Topic started by: Paul Champagne on August 10, 2015, 05:03:56 PM

Title: Roof mount Dometic Air not cold
Post by: Paul Champagne on August 10, 2015, 05:03:56 PM

Just came back from a weekend of dry camping for 4 days in 100 degree heat and noticed that my front roof air could not keep the Coach cool as the inside temp in the living room was 90 to 95 during the day the middle and back of the Coach was fine as I had all 3 AC set on high at 67 degrees my question is can the K134 be serviced as maybe they are low on Freon?

This is the first time that I haven't been able to keep the living room cold the AC unit are 9 years old... Any help would be appreciated the AC units are Dometic

Thanks

Paul 2006 Thunder

Title: Re: Roof mount Dometic Air not cold
Post by: Steve Huber on August 10, 2015, 05:47:04 PM

Paul,
I believe all roof mounted units are sealed so one cannot add freon.
Steve

Title: Re: Roof mount Dometic Air not cold
Post by: Edward Buker on August 10, 2015, 07:11:10 PM

Paul,

Those are sealed units like Steve mentioned that probably use R22. You need to see the discharge temp of that single unit running to know if it is contributing and cooling. If it is similar to other single units running in your coach then it would not be the gas. They can add a gas port, some are a mechanical tap but the best are soldered in. Given the age and difficulty/cost of adding charge if it is not working it would be better to change it out. It is hard to find and fix slow leaks in refrigeration.

Later Ed

Title: Re: Roof mount Dometic Air not cold
Post by: Paul Champagne on August 11, 2015, 01:54:31 AM

Ok I will get Beaver to test them out to see if they are working properly

Thanks

Title: Re: Roof mount Dometic Air not cold
Post by: LaMonte Monnell on August 11, 2015, 03:35:06 PM

Should be a difference of at least 20 degrees from intake temp and cooling vent temp for proper cooling.

I use an infrared temp sensor I bought at harbor freight to check mine.

Title: Re: Roof mount Dometic Air not cold
Post by: Bill Borden on August 11, 2015, 06:50:50 PM

Paul,

Our front AC unit decided to release some fluid out onto the roof (green/blue) it was either the Freon or the oil, (it was still working  but it was only a matter of time).  Either way I decided to replace it when I was told the AC units are no longer serviceable, this has been mandated by EPA, which made them tossers.  So we replaced it and the rear AC as well thinking they are the same age.

Good luck with yours,

Title: Re: Roof mount Dometic Air not cold
Post by: Keith Moffett Co-Admin on August 11, 2015, 09:54:22 PM

Paul
we had a 98 with two roof air.  They were original and working moderately well three years ago.  To  y knowlege they had never been cleaned so I checked the temp drop  before and after cleaning the fan and condenser.  I gained about 10 degrees better cooling. 
Using simple green for aluminum.  Wet the unit (cover off) from inside with a very gentle fan spray from a garden hose.
Spray simple green at about 40% strength all in the fins and fan blades etc.  Let set a few minutes but not dry.  Gently rinse hopfuly getting sand, road grime and salt etc. Out.  Might not hurt to repeat.
Do not use a stream nor shoild you rinse the fins at any angle but straight on because they bend like foil.
A/C s are not cheap and yours arent that old so this might work well for you!

Good Luck
Keith

Title: Re: Roof mount Dometic Air not cold
Post by: Paul Champagne on August 12, 2015, 03:01:30 AM

Hi Keith

I will check them out this weekend maybe they are dirty because I know my fantastic vents are always dirty!! Thanks for the tip!