Okay well first off our ac was running awesome and then one day the unit stopped spinning outside so we called a professional he came out and said that the capacitator(not sure how to spell it) burnt up which was not uncommon in this heat then he said we needed to change our filters he hosed it all down recharged the freon, a week later it compeltely freezes up, the outside unit was spinning but nothing was coming out of the vents , so we let it thaw out call him he comes out says our blower motor was getting stuck so he readjusted it said it was working already cooling our house down! Awesome except it froze up again! So we call him again and he tells us that our blower motor in our furnace needed replaced, so we replaced that ... We fall asleep to a hot house hoping it would get cooler threw the night w our running ac again only to wake up to it being frozen again ..... Please help ...
There is a wad of dust built up on the coils in the duct work that is blocking the airflow. This is a common cause of units having frostback. Your blower motor did not need to be replaced. he is replacing everything that has nothing to do with the problem. Clean the dust out of the coils (it will be like a mat of cloth) and the unit will work fine.
You AC guy, like most others I've run across, has absolutely no idea what's wrong with your system. They are taught in AC school that if this happens, replace that. If that happens, replace this. They are not taught HOW TO TROUBLESHOOT! I've had so called AC techs try to tell me that the motor will cause the capacitor to fail or the capacitor will cause the motor to fail. I've been in electronics for 43 years. It will not. A failed capacitor will prevent the motor from starting or running. Sure, he replaced the capacitor because the motor stopped running - it's a run capacitor needed for the motor. That was the easy part. Cleaning the coils by hosing them down is a maintenance action, not a repair action, unless it was extremely clogged with dirt. I doubt the blower motor was getting stuck and needed adjusting. There is no adjustments for AC motors. If the motor was bad, he should have caught that on the 1st visit. You may have bought a motor you didn't need. He's cleaned the coils and recharged the system (which I doubt was he problem either). I'm not an AC tech, but I believe you have a restriction in the refrigerant line going to the evaporator. That restriction is acting like the expansion valve causing the evaporator to ice up. A plugged or severely restricted expansion valve itself may be the problem. That's what the problem was with my unit. The restriction could also be a kinked refrigerant line going to the evaporator - that was the problem with my daughter's unit. IT'S NOT YOUR COMPRESSOR. The fact that you can create ice tells me the compressor is working. But if the problem isn't fixed soon, you could lose the compressor due to high head pressures caused by the icing problem.
