CLEAN AND CHECK HEATING UNIT. CHECK THERMOSTAT, AIR FILTER, FAN CONTROL, PROPER ENERGY CONSUMPTION, HUMIDIFIER, ALL ELECTRICAL CONNECTIONS. CLEAN AND CHECK BURNERS & BURNER OPERATION. CHECK HEAT EXCHANGER, HIGH LIMIT CONTROL, AND GAS PRESSURE. ADJUST BLOWER COMPONENT, AND LUBRICATE ALL NECESSARY MOVING PARTS. EVERYTHING IS WORKING GOOD.