My Carrier central AC has been working well... until my landlord called a technician for a "preventive maintenance". Immediately after that "maintenance" - which involved cleaning the evaporator fins with some detergent - the AC stopped cooling the house. For instance, it was cool summer night, 75F outside. The AC is running for several hours straight. The temperature in the house is... 80F. After my complaint, the technician came back, measured the exhaust temperature and left saying that everything was OK. So I had to start my own troubleshooting. I discovered that the exhaust temperature was indeed normal (between 58F and 62F), but the airflow was very weak. I opened the AC and looked at the evaporator coil. The coil was clean and shiny outside, but it was not passing any air. Somewhere deep between the fins it was entirely clogged with very hard layer of cemented dirt (which I could hardly poke through with a piece of metal wire). So I "poked" the dirt through on about 1/6 of the evaporator's area. That has greatly improved the airflow, so now my AC cools the house - although not as good as it did before the "preventive maintenance". The problem is, I cannot reach to "poke through" the rest of the evaporator coil. Is there any other way to clean the dirt between the fins? Some chemicals maybe? As I said, the layer of dirt is very dense as if it has cemented together. Another question - is it the technician's fault? Has he disturbed the dust with his detergent and made it clog the fins? Or did something else happen? Any ideas would be appreciated.
With best regards, CitizenOfDreams.