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Topic: a/c freezing up (Read 4 times) previous topic - next topic
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a/c freezing up
Yahoo Message Number: 57560
Just came back from a shake down cruise in our new 30 footer, it ran great, the A/C kept freezing up any ideas?
Re: a/c freezing up
Reply #1 –
Yahoo Message Number: 57563
Quote
Just came back from a shake down cruise in our new 30 footer, it ran great, the A/C kept freezing up any ideas?
We had the same problem.  It turned out to be a defective A/C unit, one with insufficient coolant installed.  It took me 9 months to figure out the problem and then push the system to get it replaced.  I recommend getting it to the LD factory or to a Dometic agent and insist that they fix it, preferably with a new unit.

Note:  When it comes time to remove the A/C unit, be sure to be standing there and INSIST that they not try to lift the unit before they use a saw and cut through the seal between the A/C and the roof.
LD sets that seal in body putty and if the A/C unit is just lifted, it will raise up the floating aluminum roof, ultimately stretching it.
Once stretched, it will never be the same and getting a seal will be very difficult.  This is the way Steve at the factory said to remove the unit.

Linley
Re: a/c freezing up
Reply #2 –
Yahoo Message Number: 57572
"Just came back from a shake down cruise in our new 30 footer, it ran great, the A/C kept freezing up any ideas?"

A/C freeze up is normally caused by low coolant,  low air flow( usually from a dirty air filter- unlikely in a new unit) or a defective thermostat. A quick and dirty test for low coolant is to measure the temperature of the air coming out of the vents. It should be in the low to mid 40s. Low coolant will be colder.
A miscalibrated thermostat is also a likely suspect. Many A/C thermostats can be adjusted but it requires taking the A/C unit apart to access the adjustment screw.

Since your MH is so new, LD might change it for you...maybe.
 I did not know I had a problem with the A/C in our then new 2003 LD.
It was late fall when we picked it up and the A/C worked fine the one or two times we tried it. When it warmed up a few months later, the A/C started cutting out after being run for a couples of hours. LD would not do anything, telling me that I would have to go to an 'Authorized' Dometic service center.
I found the problem, a defective thermal overload switch, but it still took four trips to the other side of L.A. to get it fixed. It almost would have been cheaper to replace the unit myself than to go through the multiple trips and the lost time and income. I even tried to buy the part outright but Dometic does not sell these parts to the general public, only to Dometic service centers.

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: a/c freezing up
Reply #3 –
Yahoo Message Number: 57575
Quote
"Just came back from a shake down cruise in our new 30 footer, it ran great, the A/C kept freezing up any ideas?"
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I have been a household appliance tech for 40+ years. Air conditioner freeze up in household window AC,s is 90 % caused buy the thermostat being set too high, or turned all the way up. I am quite sure this would be the same with an RV AC. A lot of people think that the AC will get colder faster by jacking the thermostat all the way up---Not True! Buy doing that , the AC will never get that cold to cycle the compressor off to defrost the evaperator coils, therefore causing it to frost up and eventually restrict the air flow.
The temp. control should be set only slightly higher than the middle setting, so hopefully it will get cold enough to cycle the compressor off once in awhile. In extreamly hot or humid climates the unit may never get cold enough to cycle it off unless set on even lower settings, or turned off once in awhile for manual defrost.
Hopefully that is all that is wrong with your RV AC, as that is usually the case in household AC freeze up problems.
Dan Dan the Appliance Man, in cool Colorado where we seldom use the AC except to exersize it.
Re: a/c freezing up
Reply #4 –
Yahoo Message Number: 57578
Agree with Dan on the temp setting.  Had the same problem earlier this year in Virginia with temps in the 90's and humidity about the same.
The A/C would start OK, but soon after would stop cooling.  Thought the unit (on a 2003 MB) was kaput.  Talked to Tim at LD and he told me just what Dan said.  Cut the setting back a couple of notches from Max and it now works fine.  May not be your problem, but suggest you try this.
2003 MB