AC keeps freezing up

natew_usa wrote:
Hello,

My AC unit keeps freezing up! I had a friend refill the unit with freon since it had a port so that is not the issue. I cleaned the AC unit like crazy evenused a foam coil cleaner Any other ideas? I'm think I might just replace the whole unit next year. Its a Dometic Brisk Air Duo Therm.

Thanks,

Nate

If you are talking about the cleaner that foams after it has been applied to the coils,it is meant to be used only on condenser coils and rinsed with pressurized water shortly after it has foamed. If not rinsed off,foaming condenser cleaner will destroy alluminum fins.

I agree with the other posters. They are sealed units and can only get low Freon with a leak. If yours has a fill port that indicates that it has previously had a leak which may or may not have been repaired properly.
Since you stated that you cleaned the unit completely and assuming that you are running the fan on high, especially in high humidity locations, you may well still have a leak.

Chris Bryant wrote:
If it has a port it has a leak.

Particularly if the installed port was one of the piercing types which are notorious leakers.
If a port was brazed in you have a better chance for a seal if the schrader valve is good.

Dirty filter OR dirty coils OR low on Freon OR blower fan out or running very low speed.

If it has a wall thermostat it should have a freeze sensor.... you need to get up inside and check how that the freeze sensor is placed in the evaporator coil.

If it has a port it has a leak.

Two issues can cause freeze up. The most common is insufficient airflow due to dirty filter or fan on low. Run the fan on high.

The far less common issue is low refrigerant.

You say you had to refill it? Does this mean it leaks? If so, it may be leaking out in a few minutes/hours and causing this. If not leaking, you should have a thermistor attached to the coils to detect a freezing condition and then turn off the compressor until the coils thaw then resets to turn the compressor back on. If the thermistor is not working, it could cause the unit to freeze up.

HAVING the fill port is indeed the issue. They do NOT come with fill ports. So, if you have one, someone has repaired/recharged previously. Too low of freon or too high freon will cause freeze ups. How many pounds of Freon did he put in and how did he know how much freon to install? If you have mechnical knob controls on the AC unit at the ceiling assbly, you have no freeze sensors and try running on Hi cool. If you have a wall tstat, then the unit should have a freeze sensor. Whic control system do you have? Doug

If the blower is always on high and running full time and it is not low on Freon and is that clean not sure what is going on.