PERFORM MAINT. TUNE-UP FOR 8YR HEATING UNIT. CLEAN AND CHECK BURNERS AND BURNER OPERATION. ADJUST BLOWER COMPONENTS, AND LUBRICATE ALL NECESSARY MOVING PARTS. CHECK THERMOSTAT, FAN CONTROL, AIR FILTER, AIRFLOW, HEAT EXCHANGER, HIGH LIMIT CONTROL, ENERGY CONSUMPTION, GAS PRESSURE, AND ALL ELECTRICAL CONNECTIONS.