Refrigerators have several vital functions that work together to make a useful appliance. In addition to cooling coils, air circulation, and the defrost cycle, your refrigerator also responds to the thermostat control. Or it should. The thermostat control allows you to decide how cold the fridge and freezer are. Do you want your fridge cold enough to freeze milk or just cold enough to keep the lettuce from wilting? This is your choice and it really can determine the week-long quality of your groceries. When your refrigerator is the wrong temperature but the components are working correctly, the problem can be the thermostat controller instead. If the thermostat controller is not working, your fridge will not get the signal to go colder or warmer. This can go on for months without notice if your fridge was at the ideal setting when the thermostat burned out. But if the weather or your groceries change, you will soon notice that the temperature can’t be adjusted.
To fix your thermostat control, you’ll likely need to replace the central component. We’ll walk you through it step by step.
Gather Your Supplies
Start by putting together your supplies. Have your supplies ready when you begin. You will need only two items, as this repair occurs just below surface level. So grab your screwdriver and a pair of work gloves. The screwdriver will open the thermostat control housing and the work gloves will protect your hands.
- Work Gloves
- Replacement Thermostat Controller
The last thing you’ll need is the most important – your replacement thermostat controller. Check the fridge’s make and model number, then look up its list of replacement part numbers. Find the part number for the thermostat controller and order one online. When it arrives, you’re ready to start the repair.
Pull the Power Plug
There is one safety precaution to take for this repair – you will need to cut the power. The thermostat is a powered component that connects to other wired systems. This puts you at risk of shocking yourself or shorting out a component. The best answer is to pull the plug. If you can’t reach your fridge plug, flip the breaker instead.
Disconnect the Controller Housing
Now you need to pull the housing loose, but not completely free. There will be a wire tether until you switch it out directly onto the new part. Here’s how to get the assembly loose in your hand.
- Pull the Thermostat Controller Knob
- Start by pulling the knob. Like your oven knobs, it comes right off the switch post. You can set the knob aside and clean it in the meantime during the rest of the repair, it will go on last as you finish.
- Remove All-but-One Mounting Screw
- Behind the knob and around the housing, you will see a perimeter of mounting screws. Use the screwdriver to remove them one at a time, but leave the final screw. The housing will fall when the last screw is removed.
- Support and Remove the Last Screw
- Place your hand underneath the housing as you remove the final screw. Make sure the thermostat assembly doesn’t fall or pull on the wires when it comes loose.
- Lower the Housing 6 Inches
- Lower your hand so you can see the extended wires and access the thermostat inside the housing.
Remove the Thermostat and Sensing Tube
- Hold the Housing
- Inside the housing will be a two-piece set – the thermostat and the sensing tube. The sensing tube tells the controller how cold the fridge is, and the thermostat emits controls to the cooling coils.
- Release the Sensing Tube Brackets
- The sensing tube will be held in place with brackets. Remove the screws or latches that fasten them so the sensing tube is free.
- Remove Tube Sleeve – If Necessary
- If the sensing tube is inside an insulating sleeve, remove the sleeve. You will need this to put onto the next sensing tube. If there is no insulating sleeve, don’t worry about it.
- Carefully Remove the Sensing Tube and Thermostat
- Now you can remove the sensing tube and thermostat from the housing. They will still be connected by wires.
Transition the Wires to the New Thermostat
- Snap a Photo
- The wiring transition of this piece can be easy or complicated, depending on the model. If it’s easy, you’ll have a wire harness that clips out of the old and into the new part. If it’s difficult, you will need to transfer specific wires to specific prongs. If the latter, snap a photo with your phone before removing the wires from the original part.
- Unpack the New Thermostat
- Remove the packaging from your new thermostat and prepare to install it. Make sure all the plastic and tabs are removed.
- Straighten the Sensor Tube
- Uncoil the sensor tube from the thermostat and straighten out.
- Transition Tube Sleeve – If Necessary
- If the original sensing tube had an insulating sleeve, you removed it earlier. Grab that sleeve and slip it over the current sensing tube. If you didn’t get a sleeve, don’t worry about it.
- Transition the Wires
- Now take another look at those wires. Transition them carefully from the old thermostat to the new thermostat. If it’s a wire harness, task is easy. If you need to go prong-by-prong, the transition method is the best way to be precise. If you aren’t sure, check your photo.
- Check Your Photo
- Double-check the wire transition with the photo to ensure it looks exactly the same.
- Attach the Sensing Tube Brackets
- Secure the brackets that hold the sensing tube in place.
Reassemble Your Refrigerator
- Secure the Thermostat Housing
- Push the housing into place, then return each of the mounting screws. Tighten them enough to be secure, but do not over-tighten or you risk cracking the plastic.
- Return the Knob
- Grab that thermostat knob and set it back onto the switch post. Make sure it is facing the correct direction so that the markings indicate an accurate setting.
- Plug the Fridge Back On
- Finally, plug the refrigerator back in and allow it to reach your indicated temperature. Use a fridge-safe thermometer to confirm that your thermostat controller is working once again.