CLEAN AND CHECK 8YR HEATING SYSTEM. CLEAN AND CHECK BURNERS AND BURNER OPERATION. ADJUST BLOWER COMPONENTS, AND LUBRICATE ALL NECESSARY MOVING PARTS. CHECK HEAT EXCHANGER AND HIGH LIMIT CONTROL. CHECK MANIFOLD GAS PRESSURE AND FOR PROPER VENTING. CHECK THERMOSTAT, AIR FILTER, AIRFLOW, FAN CONTROL, ENERGY CONSUMPTION, HUMIDIFIER, AND ALL ELECTRICAL CONNECTION.