Air conditioner freeze up???

[RevHam]

Howdy All -

Wife and I are presently in Charleston, SC (Oak Plantation CG). It is very hot & humid. We went to church early this morning then on to some site seeing. We arrived back at the CG after 5. When my wife went in to the RV, it was warm and stuffy. The air had been left on all day but . . .
I could hear the blower - a little cool air was trying to come out but nothing blowing. Fuses are fine. On inspection of the roof unit, there appeared to be some things frozen over. At this point - 2 hours later, the ice has melted/fell off the components. I have not tried the AC yet.
Any thoughts/suggestions?

[RevHam]

I was told when it's really hot outside to run the AC on high.I always run mine on high and have never had a problem with the unit freezing up.

Were you running your Ac on low or high?

Charles

I do believe the blower was on low and the temp was set at 67.

[gmarker]

Trying to get to 67 degrees with the fan set on low and high humitity is almost guaranteed to freeze up your evaporator. Turn both the temperature and the fan up. Also, be sure the filter is clean and all of the a/c vents are open. Hope this helps.

[jennyt]

We have had ours freeze up once with high humidity - we were able to turn it off for about 30 mins and in the TX heat that's all it took for it to defrost. It sounds like the fan speed is a good thing to remember too.

[Mike Clay]

I have had them freeze on high also, once in Vegas no humidity there just one poor air conditioner trying to cool down a trailer when it was 108 outside.

[gmarker]

The only thing that I have had freeze up in Las Vegas was my bank account. I don't think the temperature or humidity had anything to do with it........ although there was a lot of ice in my drinks.

[RevHam]

Hope this helps.

Thanks everyone! I followed the advice - blower on high & temp up. So far, so good!

[Olbird]

RV air conditioners are known to freeze up from time to time, as others have stated put the fan speed on high to keep a good flow of air across the evaporator.
It will not damage the unit to turn the fan back on after a freeze up, this will help it defrost faster ( fan only) once fan starts moving a good flow of air again you can start the compressor again. The unit may blow ice and water out at you as it defrosts.

If the unit starts freezes up all the time have the a service person check the freon pressures, the evaporator will also freeze up if low on freon. RV units have to operate real close to exact proper freon charge in the system.

I have had new RV AC units loose very small amounts of freon within the first year and need a little freon added to prevent freeze-up and never could find a leak with the best of industrial leak detector equipment.

Hopfully low freon is not your problem and only low air flow across the evaporator is the problem.

George:

[mcdonell8]

My two cents.

RV a/c units are sealed and do not have service ports. Meaning in theory there is no possibility of a leak of refrigerant (freon) and usually technicians do not use gages to determine if system is fully charged.

Freeze up, especially on a rv, is usually an air flow issue. Low fan speed by itself should not cause a freeze condition. The system is designed for the low fan speed and should not freeze temperature even running continuously, regardless of the setting.

That said, many parts of the system can contribute to the problem. The low fan speed probably was a factor, but I suspect another issue would have to also be involved. I would look first for a dirty filter, dirty evaporator coil, or closed/restricted duct vent.

Thats my two cents.

[Mike Clay]

There is a sensor that is suppose to prevent this, not sure if its in all the brands but my friend had one go out in his rig.