AC still Freezing up.

[G McCall]

While camping over the weekend, the AC tried to Freeze up (again).
I have replaced the factory on/off control with a digital control and was running the unit on high fan. Actually high fan is the only way the new digital control works unless I add another single pole switch for fan speed control.

Once I moved the temp. control to a higher level of 75° so the compressor would cycle, all was okay, except it was warmer in the trailer.
Latter that night I lowered the temp setting to 69° and the unit cycled okay. I tell ya this trailer is "jinxed"
and yes..... (I like to be cool when camping.)


ANYWAY, about a fix........
This trailer is only 5 months old and I have had this problem before.
The coils begin to freeze at the top and works its way toward the little freeze sensor that is positioned near the bottom of the coils. The air flow dimenishes dramatically.
If the Freeze sensor is even working, should it be moved towards the top of the coils ? Is the sensor supposed to be pushed in all the way ?

[Charlie]

It should not be freezing up, take it back to the dealer while still under warranty and let them figure it out.

[Montana Sky]

I am having the same problem with my main a/c AGAIN as well. I run the main a/c with the switch selected "on" and "high". I do not use the auto setting as this causes the compressor to cycle to often. I have had the shop look at this over the past 2 years, last year they adjusted something. This year they resealed the return airbox, said it was leaking and sending cold air onto the coils causing them to freeze. Well 2 weeks ago it was 78 outside and I had the a/c set at 72 inside, left for 4 hours and when I came back, the a/c was hardly running-almost no air movement. Shortly after that, it tripped the breaker and shut off. This is not the first time of tripping the breaker, happens all the time. Another reason I had the 2nd a/c installed. I will be heading to the dealership to see what they recommend the next "fix" to be. I think it is time to replace the entire unit myself, have to wait and see.

[G McCall]

Montana Sky, your AC trouble sounds like mine.
My trailer is parked at my deer lease 220 miles away, which makes it difficult to run it by the dealer or try the rememdies you guys have in a timely manner. Still, I am taking notes amd hope to figure it out the next time we camp. Worth a shot.

[Ozz]

Check the temperature difference between the outlet of the evaporator and the room air return, should be 20, maybe 25 degrees difference. When a coil freezes uniformly it is an airflow problem, when it freezes on one area first, and you have a bottom, or top that is ice, and the other end dry, it is low on refrigerant.
Keep those filters spotless, I imagine that the ducting is not really as it should be size wise.
A good test is to open the dump damper, (drops supply air directly down from the unit), if it still freezes the coil on high fan speed, it is probably a low charge and small leak issue.
Good luck. Jim

[Dustytuu]

Ours is freezing too. We run it on high most of the time. But it will freeze on high or low. We finally removed the filter and intake vent and it still freezes! We can not depend on it. Can't leave the dogs in the trailer while we go someplace because it will freeze up.
It is at a montana dealer now having them look at it again. This is the second time. They are also installing a second air conditioner too while it is there.
Hope they replace the whole main air conditioner this time.

[Gonfishin]

Just out of curiosity how many of you with freezing A/C's are running the CCC, how many are using the ole remote or the older thermostat? I have had mine freeze up one time and that was in Denver when it wasn't very hot with extremely low humidity. BTW aren't they supposed to have some sort of freeze guard to protect from this?
Rick.

[G McCall]

My AC has not frozen up again since I started running the unit on high Fan. I also switched my control to a wall mounted digital read unit. I did not and do not have a remote control. unit.

[Ozz]

Cool.........

[DHenry]

Dometic has a service bulletin out on the A/C, if any of you would like it please email me your email address and I will send it to you.