Upon arrival customer stated washable filter is not fitting in return at air handler and he noticed system freezing up. Tech tested system operation and found pressures within spec in heat and cool mode. Tech did find filter to be wrong size and not fitting properly. Tech installed a temporary filter off truck for now. Will need to get a 20x23x1 washable filter and return with filter. System is operating properly. Tech found light buildup of lint on return side of coil but not enough to cause system to freeze, tech cleaned lint off coil. No charge per install warranty per office.