MAINTENANCE TUNE-UP FOR 3 YEAR HEATING UNIT, DIRTY. CHECK THERMOSTAT, HEAT EXCHANGER, HIGH LIMIT CONTROL, FAN CONTROL, AIR FILTER, AIRFLOW, ENERGY CONSUMPTION, AND ALL ELECTRICAL CONNECTIONS. CLEAN AND CHECK BURNERS AND BURNER OPERATION. CHECK MANIFOLD GAS PRESSURE AND FOR PROPER VENTING. LUBRICATE ALL NECESSARY MOVING PARTS AND ADJUST BLOWER COMPONENTS. EVERYTHING IS RUNNING GOOD.