TUNE-UP ON A 9YR HEATING UNIT. LUBRICATE ALL NECESSARY MOVING PARTS, ADJUST BLOWER, COMPONENTS, CHECK MANIFOLD GAS PRESSURE AND FOR PROPER VENTING. CHECK THERMOSTAT, AIR FILTER, HUMIDIFIER, HEAT EXCHANGER, HIGH LIMIT CONTROL, FAN CONTROL, ENERGY CONSUMPTION, AND ALL ELECRICAL CONNECTIONS. CLEAN AND CHECK BURNERS AND BURNER OPERATION.