1ST MAINTENANCE TUNE-UP PER SERVICE AGREEMENT FOR 4 YR HT UNIT. CHECK MANIFOLD GAS PRESSURE AND FOR PROPER VENTING. LUBRICATE ALL NECESSARY MOVING PARTS AND ADJUST BLOWER COMPONENTS. CLEAN AND CHECK BURNERS AND BURNER OPERATION. CHECK THERMOSTAT, HEAT EXCHANGER, HIGH LIMIT CONTROL, FAN CONTROL, AIRFLOW, AIR FILTER, ENERGY CONSUMPTION, AND ALL ELECTRICAL CONNECTIONS. EVERYTHING IS OPERATING GOOD.