CLEAN AND CHECK 3 YR HEATING UNIT. CLEAN AND CHECK BURNERS AND BURNER OPERATION. CHECK HEAT HIGH CONTROL. ADJUST BLOWER COMPONENTS, AND LUBRICATE ALL NECESSARY MOVING PARTS. CHECK HUMIDIFIER, THERMOSTAT, AIR FILTER, AIRFLOW, COMPRESSOR DELAY SAFETY CONTROL, ENERGY CONSUMPTION, AND ALL ELECTRICAL CONNECTIONS. EVERYTHING IS OK.