1ST CLEAN AND CHECK UNDER SERVICE AGREEMENT FOR HEATING UNIT. CUSTOMER HAVE 2 UNITS. CLEAN AND CHECK BURNERS AND BURNER OPERATION. ADJUST BLOWER COMPONENTS, LUBRICATE ALL NECESSARY MOVING PARTS, AND CHECK ALL ELECTRICAL CONNECTIONS. CHECK THERMOSTAT, AIR FILTER, HUMIDIFIER, HEAT EXCHANGER, HIGH LIMIT CONTROL, ENERGY CONSUMPTION, AIRFLOW, FAN CONTROL, AND MANIFOLD GAS PRESSURE AND FOR PROPER VENTING.