Rear A/C Freezing

[POWslinger]

We just purchased a new unit about a month ago and every time the rear A/C unit runs the coils freeze. We are in southern PA so it has been pretty warm (high 80's low 90's) and humid. The front A/C runs without freezing so that makes me question that the problem might be with the unit itself. I've checked the air box and that seems to be good and I have also moved the coil thermostat from the lower right hand corner to the bottom center and up 2". After moving the thermostat, instead of the entire thing freezing...now it freezes except for below the thermostat location. I am thinking about moving it a little higher on the coil but if there is a bigger problem at large I do not want to just band aid a brand new unit and have it fail catastrophically outside of the warranty period. Any thoughts?

I've tried to get a service appointment (scheduled 2 weeks ago) but the first one is not until Sept 1st. And that is just to diagnose the several issues I've had. So far I am not impressed with the GD "Quality".

Thanks in advance for any input!!

[Country Campers]

Try running the fan on low instead of auto, this has helped ours out.

What brand of AC is it?

Brian

[SolitudeAtLast]

Our front a/c started freezing up after 6 months. I also tried moving up the sensor a couple of times. It would freeze coils down to the sensor, which which then shuts off compressor; so prevents freezing by shutting off compressor. Mine was a Coleman. See my post by searching on a/c evaporator coil freezes. Still in warranty covered by Coleman, replaced by 3rd party (RV Doctors), so I had to pay for the service call travel. Called GD first to make sure ok to use local repair service, and to document the problem. RV Docs was in our campground regularly, recommended by other campers, and used to dealing with warranty issues like this. Good Luck!

[OffToHavasu]

Freezing coils is generally caused by one of two things: air flow or low charge.

If you're not getting enough air flow across the coils (plugged filters, a bunch of closed vents) the coils will freeze up.

Oddly enough, a LOW charge will cause coils to freeze over as well. These units are non-serviceable and if that's the case, the unit will need to be replaced.

[Jlawles2]

Check to see if the rear unit has an RVAirflow. There was a report of one being installed incorrectly leading to a few issues.

If the unit is low and you have a good AC guy, they can add a fill port. However, if it's low, it's either leaking or was originally under charged. With the unit at less than a 6 months old, I would insist on replacement.