I know this subject has been raised over and over, but of course I paid no attention until I actually had the problem myself. Picture a central air system that's been no trouble (unless you count the dead snake I had to fish out of the compressor fan once) until, naturally, the hottest days we've had in several years (and I do understand about "design point"). Cool-ish air from the vents and not much of it, so of course I realized I'd let the filter go too long. It was dirty, my A-coils were blocked and encased in solid ice so I thawed it all out, replaced the filter, cleaned the A-coils, opened and cleaned the coils on the outside part of the unit, and everything worked fine for about 24 hours. Then the same problems -- not very cold air (8 deg F temperature differential) and iced-up A-coils. I found some leaky seams on the back side of the ductwork and figured too much air was bypassing the coils, which I thought might have caused the new freeze-up (I got a D in Thermodynamics in college, so I might be totally wrong about that). Fixed the air leaks, reopened and re-cleaned the outdoor parts just to be sure, and waited several hours to see if things would improve. I get a lot more airflow from the vents but it's still only 8 deg F differential, so I'm thinking low freon -- which finally leads to my question: Can low refrigerant and coil freezing go together, once the coils have been thoroughly cleaned and air leaks sealed? The big copper line into the unit was ice-cold when all this started but is just barely cool today. I'm trying to nurse this thing through one last summer -- my daughter's finally out of college and I can use the money I usually spend on her tuition to replace the unit in a few months, if repairs aren't feasible.
- Steve Richardson St Louis MO