2ND MAINTENANCE TUNE-UP FOR UNDER SERVICE AGREEMENT ON 2 HEATING UNITS. RENEWED SERVICE AGREEMENT. CLEAN AND CHECK BURNERS AND BURNER OPERATION. CHECK MANIFOLD GAS PRESSURE AND FOR PROPER VENTING. LUBRICATE ALL NECESSARY MOVING PARTS AND ADJUST BLOWER COMPONENTS. CHECK THERMOSTAT, AIR FILTER, AIRFLOW, HUMIDIFIER, HEAT EXCHNGER, HIGH LIMIT CONTROL, ENERGY CONSUMPTION, FAN CONTROL, HUMIDIFIER, AND ALL ELECTRICAL CONNECTIONS.