How to Fix a Kenmore Refrigerator Diffuser

How a Diffuser Works

• Air flow between the refrigerator and freezer compartments of a Kenmore refrigerator is controlled by the air diffuser, which is set into the wall between the compartments. The refrigerator is cooled by air it receives from the freezer through the diffuser. The diffuser is connected to the refrigerator’s control panel and a thermistor. A thermistor, or thermal resistor, responds to temperature fluctuations with accurate changes in its electrical resistance. Based on the thermistor’s changes, the diffuser opens or closes a chamber, allowing air to flow from the freezer to the refrigerator to achieve and maintain a specific temperature.

Symptoms of Diffuser Failure

• Before you decide to replace your Kenmore refrigerator's diffuser, you should make sure it is faulty. A typical problem that could indicate diffuser failure is food spoiling in your refrigerator before its expiration date. If your refrigerator's controls are set properly and the freezer is cooling properly but the refrigerator isn’t, a defective diffuser or thermistor are possible causes. Lack of air movement through the refrigerator’s vents also is a sign of diffuser trouble.

Obtain a Replacement Diffuser and Thermistor

• You can order a replacement diffuser and thermistor directly from Sears, or purchase them from an appliance retailer that sells Kenmore replacement parts. Sometimes installation instructions will accompany the replacement parts. If you don't receive instructions, contact Sears or a Kenmore dealer for help obtaining them. The instructions are helpful to use for guidance, as they often contain a diagram.

Replace the Diffuser

• Unplug the refrigerator. Locate your refrigerator's diffuser. On a side-by-side Kenmore refrigerator, it’s in the upper left corner of the refrigerator compartment. Review the manual to confirm its location in other refrigerator configurations. To access the defective diffuser, you must remove two plastic covers -- one for the wire chase and one for the diffuser -- by loosening their screws and lifting off the covers. Also unscrew the freezer component next to the diffuser to remove it. Pull back the diffuser’s locking tabs on the freezer side, and slide the diffuser out from the refrigerator side after disconnecting its wire connector. Insert the replacement diffuser from the refrigerator side, and attach its locking tabs on the freezer side to secure it in place. Connect it to the wire connector. Reattach the freezer component and the two plastic covers by reversing the removal process.

Replace the Thermistor

• You may need to replace the thermistor when you replace the diffuser as both components work together. With the refrigerator still unplugged, disconnect the thermistor wire from the existing thermistor. It’s the black wire contained by the wire chase cover, which you removed when you removed the original diffuser. Disconnect the wire from its white plastic wire connector, and insert the wire in the new thermistor. Remove the existing thermistor that’s taped behind the diffuser cover, and replace it with the new one.