MAINTENANCE TUNE-UP FOR 16YR UNIT. CHECK AIR FILTER, THERMOSTAT, HUMIDIFIER, HIGH LIMIT CONTROL, HEAT EXCHANGER, ENERGY CONSUMPTION, FAN CONTROL, GAS PRESSURE, AND ALL ELECTRICAL CONNECTIONS. CLEAN AND CHECK BURNERS AND BURNER OPERATION. LUBRICATE ALL NECESSARY MOVING PARTS, AND ADJUST BLOWER COMPONENTS.