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