How to Test an Ice Maker Thermostat

Turn the thermostat up and down to see if this alters the ice maker's performance. Some models have a separate thermostat for the ice maker and the freezer, while others have one that controls both. Check your manual if you aren't sure which applies to your specific fridge. Wait several hours after changing the thermostat setting to see if the freezer and ice maker gets warmer or colder as a result.

Unplug the fridge before touching the ice maker to eliminate the risk of an electrical accident. Empty any ice out of the ice maker as well so you have easier access to it.

Examine the ice maker to see if you have a modular or component ice maker by prying the faceplate off with a flat-head screwdriver. A component ice maker has several gears visible under the faceplate. A modular version has several holes with each showing a letter. The type of ice maker you have determines how to test it.

Insert one probe of a multitester into the hole of a modular ice maker marked "T," and the other probe into the hole marked "H" when the freezer is cold. Set the ohms on the multitester to "X1." You should get a reading of zero. Let the ice maker heat up to room temperature and retest. The multitester should now read infinity. If it doesn't, replace the thermostat.

Unscrew a component ice maker from the freezer unit by undoing the two bottom screws with a screwdriver and then taking the top two out as well. The ice maker then pulls right out of the freezer. Unplug the wiring harness to unhook it completely.

Unscrew the mounting plate from the front of the component ice maker. Disconnect the two or three wires from the thermostat near the bottom of the support box. Pull the thermostat out and let it warm to room temperature.

Hook up a multitester unit to the thermostat by placing a probe on each wire of the thermostat. Again set the ohms on the multitester to "X1." The reading should show infinity if the thermostat is working properly. Place it in the freezer for 20 minutes to cool it down and then retest. Now it should show a reading of zero. Replace the thermostat if this is not the case.