Duo Therm AC freezing up
It happened twice just this weekend and also a once a couple weeks ago. Once I get it thawed out it works fine again. Any idea what to look for as a cause. Neighbor thought maybe refrigerant was low. ...
Forum Discussion
You can check for proper charge on a R22 unit with a clamp-on ammeter, but most people don't know how to do it. The usual response on this forum for just about any air conditioner problem, and usually the incorrect one is low freon. Also, the non AC people won't realize that the newer units are charged with R410A, instead of R22. R410A runs at very high pressures and the high side pressure tends to be unstable and changes a lot with ambient temperature. That means you can't just have your local AC guy come out, sweat a service valve on, slap the gauges on it and charge it until the pressures "look" right. These units have to either have an exact charge weighed into them or they have to be charged by superheat, and they have to be charged as a liquid as opposed to R22 vapor charging.
R410A is a 50/50 blend of two different refrigerants. Since the two have different weights and molecular structure, a leak results in an imbalance because the two refrigerants leak at different rates. That blows your 50/50 mix.That means, if you actually do have a leak, the system must be evacuated, vacuumed, and recharged. These units are no longer shade tree repairable.
R410A is a 50/50 blend of two different refrigerants. Since the two have different weights and molecular structure, a leak results in an imbalance because the two refrigerants leak at different rates. That blows your 50/50 mix.That means, if you actually do have a leak, the system must be evacuated, vacuumed, and recharged. These units are no longer shade tree repairable.
