13 POINT TUNE-UP ON HEATING SYSTEM. CHECK THERMOSTAT, AIR FILTER, HUMIDIFIER, FAN CONTROL, HEAT EXCHANGER, HIGH LIMIT CONTROL, AND ALL ELECTRICAL CONNECTIONS, CLEAN AND CHECK BURNERS AND BURNER OPERATION. LUBRICATE ALL NECESSARY MOVING PARTS, AND ADJUST BLOWER COMPONENTS. CHECK GAS PRESSURE AND FOR PROPER VENTING.