2ND MAINTENANCE CHECK-UP UNDER SERVICE AGREEMENT FOR 7YR HEATING SYSTEM. SOLD GUARDIAN. RENEWED SA. UV UPGRADE SHOT. CLEAN AND CHECK BURNERS AND BURNER OPERATION. CHECK HEAT EXCHANGER AND HIGH LIMIT CONTROL. LUBRICATE ALL NECESSARY MOVING PARTS AND ADJUST BLOWER COMPONENTS. CHECK MANIFOLD GAS PRESSURE AND FOR PROPER VENTING. CHECK THERMOSTAT, AIR FILTER, AIRFLOW, ENERGY CONSUMPTION, HUMIDIFIER, FAN CONTROL, AND ALL ELECTRICAL CONNECTIONS.