FIRST CLEAN AND CHECK UNDER SERVICE AGREEMENT FOR 4YR HEATING SYSTEM. CHECK THERMOSTAT, AIRFLOW, AIR FILTER. FAN CONTROL, ENERGY CONSUMPTION. HUMIDIFIER, AND ALL ELECTRICAL CONNECTIONS. CHECK HEAT EXCHANGER, HIGH LIMIT CONTROL. CLEAN AND CHECK BURNERS AND BURNER OPERATION. LUBRICATE ALL NECESSARY MOVING PARTS, AND ADJUST BLOWER COMPONENTS.