Performed 1 system heating maintenance. Observed no form of power protection. Recommend installing surge protector to keep electrical components from damage. System requires combustion calibration to adjust firing rate within acceptable ranges. Blower wheel minimally dirty. Chemically Cleaning wheel may increase efficiency to a small extent. Cleaned drain line and added union. Please send customer paper copy. Performed combustion calibration and installed surge protector. Changed 16x25x5 media filter.