Performed the level 2 package cleaning. Furnace: Burners and flame sensor are clean. Heat exchanger is rusting and chipping, however, no cracks located. Combustion readings were normal. No CO detected in the air. Drain is clear. Heat rise was 51Â°. AC: No leaks detected. Electrical components tested good. Condenser coil is clean. Refrigerant charge was normal. Superheat was 26Â°. All equipment is operating properly.