Came out today to investigate a Goodman AC system that froze last week. Model #Gsz130421ah, serial #1408196842. Upon arrival the system was in the off position at the thermostat. I ensured that the air handler and condenser were completely thawed out. I powered down the system and removed the access panel. (This system was installed backwards, the access panels face the wall). I found a completely clogged air filter dated Aug/2021. I replaced the 20x20x1 air filter. I re attached the access panels and powered the system up. I called for ac and observed the system operating normally. Performed preventative maintenance. I powered the system down and removed the access panel. The evaporator coils are in fair condition. I tested the drain pan and drain line to ensure that there are no leaks or clogs. The blower wheel is clean and in good condition. I checked all electrical connections to ensure that they were secure and in good condition. I re attached the access panels and powered the s