I purchased a Cedar Creek 36B4 Fifth Wheel in April of 2012. It has a ducted Dometic 15K Air Conditioner (Model#541816)in the rear.I noticed the ac wasn't cooling in Oct 2012. Brought it back to the dealer (Lazy Days in Tampa), they confirmed and replaced the unit under warranty. I noticed the ac wasn't cooling around January 2014. I called the closest Dometic warranty dealer (in Punta Gorda, FL). They confirmed and replaced the unit. Now it's January 2015 and it's not working again. The third unit! My local Dometic warranty dealer submitted a claim but Dometic denied the claim as it has been over two years.I need to know what is going on here. I don't want to purchase a fourth unit only to have it fail in a years time.Facts: We live in Florida. We used the fifth wheel for 10 continuous weeks during the summers of 2012, 2013, 2014 to travel to Bar Harbor Maine (Wicked good Lobstah!). When we are not using it we keep it in a covered storage building with 50Amp service. I set the ac thermostat to 84 degrees to keep the humidity at bay. The Dometic dealer said keeping it plugged in this way should not cause premature failure. Any ideas? I am at a loss and refuse to believe these failures are a coincidence. Please advise. Thanks in advance.

It may be possible that either the storage building electrical outlet is not supplying the correct voltage (under-voltage) or some of your usual camping sites have brown-out conditions. Your generator may cause the same problem.Have you monitored the 120v ac voltage at one of your outlets in the RV?

How did they fail? Did they leak the refrigerant, or did the compressors fail?"Not cooling" covers a lot- the specific failure would help in figuring the underlying cause.

Need more information on cause of failures.

if it runs while in storage means it is running constantly off & on on a 24 hr per day for how many years? Wonder how many hrs are on the units when they fail? I would not plug it in and run the a/c all the time. These are not quite like home units.

Sounds like voltage issue either in 5th wheel or the power source

3rd AC failure in 3 years | Good Sam Community

18 Replies

TTguy
Explorer
Oct 27, 2015
So I installed the fourth unit myself spring 2015 and have stopped running the a/c while it is in storage. I really cleaned up the hole in the roof with aluminum/duct tape to make sure I got a really good seal. SO far so good but I still don't know why the others failed. I figure if they only work so long if I reduce the use I may get longer then a season out of them. Good luck everyone with problems.
itguy08
Explorer
Oct 27, 2015
My guess is it has to do with the new refrigerant. The R140a they are using now needs higher pressures to work vs the R22 and R1434a they used to use. But I'm no AC guy.

There were a few guys who, out of warranty replaced their Domestics with the Atwood ones and they seem happy. About the same price, 2 year warranty, so it may be an option.
j-d
Explorer II
Oct 27, 2015
^^^ Maybe by Years Three Four and Five Dometic will have corrected whatever's letting the refrigerant out. Maybe by going back to whatever kept the refrigerant in before somebody said they could save $1.11 a unit by....

Discussions on RV.net have seemed to trend in the direction of Coleman and Dometic having about equal reliability. We've had only two RV's and both had plain vanilla Coleman A/C. Not ducted, no wall thermostat, no heat pump, no heat strip. Just old "window shakers" adapted to rooftop configuration with a $150 plastic shroud.

First Coleman (13500) ran to Age 25 with a cleaning, a shroud, and oiling the blower.

Second Coleman (15000) has run since 2002 with a cleaning and a blower motor. That includes over three years fulltiming.

What's changing? I've thought that if I had to replace our current Coleman I'd look for features and price between Coleman and Dometic. Now I'm thinking I'd look for the best deal I can get on Coleman.
itguy08
Explorer
Oct 27, 2015
Lots of info here but my guess is it's a Dometic issue. There are LOTS of them that just go bad lately. Seems with the new models they used a thinner metal for the coils and it rubs and leaks out.

Happened to us this year - brand new unit, on the 4th trip it started going and by the 5th it was done. Compressor would run, fan would run but in the shade and 85f it was blowing 75f air at best.

Diagnosis - bad unit. Not voltage, not wiring, nothing but lost refrigerant. There are guys in the Open Range forums on their 5th Dometic in a couple years! Luckily we bought the extended warranty so when it happens in years 3-5 we're covered.
Charles2222
Explorer
Oct 27, 2015
Dometic is the problem!About 18 Mo needed three,all with a loss of refig!
PamfromVA
Explorer
Oct 26, 2015
We are on our third AC/heat pump. The previous two lost freon. Don't know why but we are hoping third time is the charm.
Happy_Cougar_Ca
Explorer
Oct 26, 2015
I am 18 month in on a Keystone Cougar and I just had my 4th ac failure, in this unit, with a Dometic. This is my 8th. rv and they have all been stored and used the same and this is the first time I have ever had a/c problems.

The original kept freezing up. The first replacement did the same. The second replacements compressor won't come on. It's in the shop again.

I feel your pain!
gatorcq
Explorer
Feb 04, 2015
Golden_HVAC is correct in his assumptions. I would be looking at voltage/cable size to the AC unit. Bad/loose connections in the breaker bot. Do you have a transfer switch? Automatic or manual?
Any unit should be able to handle 24 hours a day. In fact working longer is a plus.
Another issue could be the supply / return air vent. Is it the required Min.
TTguy
Explorer
Feb 03, 2015
I keep the fifth wheel in a 40x60 steel building with 3 14 foot doors and a 16 foot top height. There's about 4 feet above the ac. We kept it there beginning in Feb 2014 (That's when we bought the house). Prior to that we kept it at a public storage facility that had a covered roof with open sides. Both places had 50amp service. I have always used the SurgeGuard 50amp protector. It's reading 123V tonight and usually does. I unplugged the RV and put the meter to the surgeGuard and both legs are reading 124V. Paperwork: The Oct 2012 replacement traced the problem to a leak. The March 2014 replacement says it was low on refrigerant. I can't be 100% sure but that what it says.
dougrainer
Nomad
Feb 03, 2015
Can you post a pic of your covered storage building? Does this building have doors and the RV is ENCLOSED? Or is there no doors and the entrance is fully open? How much clearance from the roof AC to the building ceiling is there? You really need to find out what the ACTUAL failures were on the previous units. Dometic replaces for only 2 things. 1. Compressor failure. 2. Leak in the sealed system. IF compressor failure all 3 times in 3 years, sorry, YOU are doing something wrong causing the compressor's to fail. Either lack of ventilation or low or high voltage. Doug