CLEAN AND CHECK ON THE 2ND SERVICE AGREEMENT FOR 3YR HEATING UNIT. CHECK THERMOSTAT, AIR FILTER, FAN CONTROL, AIRFLOW, HUMIDIFIER, HEAT EXCHANGER, HIGH LIMIT CONTROL, AND ALL ELECTRICAL CONNECTIONS. CLEAN AND CHECK BURNERS AND BURNER OPERATION. CHECK MANIFOLD GAS PRESSURE AND FOR PROPER VENTING. LUBRICATE ALL NECESSARY MOVING PARTS, ADJUST BLOWER COMPONENTS.