Furnace Maintenance: Adjusted the control board e20 jumper to working with the single stage thermostat to operate into second stage. Replaced the media filter for optimal airflow 16x25x5 (x6672). Flushed the condensate P-trap and drain lines to maintain clear, efficient flow. Checked pressure switch tubing to ensure reliable performance. Cleaned and polished the flame sensor for optimal ignition. Ran full diagnostics to confirm the system is running smoothly and efficiently.