Performed preventative maintenance for 2 high efficiency furnaces. One system is in the basement and the newer system is in the attic. Attic system was replaced in June 2019 and had free maintenance for 3 years per system sale agreement. The maintenance today for the attic system is the last FWI maintenance. Maintenance in the spring 2023 will be the first charged maintenance for the attic system. Replaced both filters supplied by the customer (Merv 11- 16x25x5). Even though the filter was replaced in the basement In the fall it was still fairly dirty that it wouldn’t last the coming winter season. The attic filter was last replaced in the fall 2021. Inspected all the electrical components. Replaced customer supplied #35 water panel for power humidifier in the basement. Cleaned the burners, flame sensors and burner compartments. Made sure all condensation tubing was clear of debris and/or blockage. No blockages found at this time. Tested the amp draw for the blowers and inducers of bo