CLEAN AND CHECK HT. CHECK THERMOSTAT, CHECK HUMIDIFIER, CHECK MANIFOLD GAS PRESSURE AND FOR PROPER VENTING. CHECK BURNERS & BURNER OPERATION, CHECK HEAT EXCHANGER. CHECK CONDENSER COIL, CHECK AIR FILTER, CHECK DRAINAGE, CHECK ALL ELECTRICAL CONNECTIONS. ADJUST BLOWER COMPONENTS, LUBRICATE ALL NECESSARY MOVING PARTS. EVERYTHING IS RUNNING GREAT.