2025 PCSA Heating Check Up Prepaid Heating Maintenance Checked wire connections. Replaced filter. Flushed drain line. Thermostat was operating normally. Burners were clean. Cleaned flame sensor. Control board was free of codes. CO levels were within normal range. Puron levels were within normal range. Defrost mode was operating normally. Everything was clean and checked out well. System is operating normally at this time.