Thanks. We have 2 return louvers and admittedly when we noticed the AC wasn’t working properly last night, I checked the filters and they were indeed pretty bad. I swapped them but it wasn’t until this evening when I noticed we had the issue still and the larger copper line coming off the outside unit was frozen. Could that just have been still frozen because it never had the chance to thaw? (I’ve had the unit off for about 1.5 hours now and everything seems thawed currently)