Furnace Maintenance: Flushed the condensate P-trap and lines to ensure proper drainage. Inspected pressure switch tubing for functionality. Cleaned and polished the flame sensor to optimize performance. Conducted diagnostic testing, confirming the system is operating efficiently. Vaccummed the ventilation system. Furnace is operating beautifully. Changed batteries to thermostat and explained fan options of “on” running all the time and “auto” until set point reached. Happy New Year,