Performed level 2 furnace cleaning. Burners and flame sensor are clean. Heat exchanger is showing minor signs of wear. Gas and exhaust levels are normal. No CO detected in the air. Drain is clear. Heat rise was 44*. Investigated the humidifier. It appears to be okay. Display shows 39%. Might not be kicking on due to the warmer and damp weather. Unit is operating normally at this time. Thank you for choosing Black-Haak! Please take the time to complete our online