Testing and Calibrating Your Oven Thermostat Sensor
If it is taking longer than usual to prepare food in the oven, it indicates that the thermostat sensor could be a problem. The thermostat of the oven is a switch that opens and closes in response to the temperature inside the oven. The switch is normally located in the control panel of the machine. The thermostat uses a liquid-filled bulb that is capable of sensing the temperature and is responsible for maintaining the internal temperature of the oven by regulating the supply of heat.
Before you check the condition of the thermostat, you must disconnect the power supply to the appliance. Also, remember that many electrical checks are high-voltage tests and should be done under the supervision of a range repairman. If you are attempting range repair for the first time, it is best to call an oven service technician. These trained professionals have years of experience and will visit your house to service your household appliance.
Locating the Thermostat Switch
The location of the thermostat depends on the make and model of the oven. Here is how you can access it:
- Freestanding Models: The thermostat is usually located on the rear side. Remove the screws holding the back panel to the body to access it.
- Front-Loading Controls: Remove the machine panel and tilt it slightly. Be careful not to disconnect any internal wiring while tilting.
- Removable Backsplash: Lift the backsplash and rest it on your cooktop after removing the mounting screws.
- Wall Ovens: Access the control panel by opening the oven door and removing the screws located below the panel or underneath the exhaust hood.
- Trim-Mounted Panels: In some ovens, you may have to remove the decorative trim to reach the screws that attach the front and rear control panels.
Checking the Condition of the Switch
Once you locate the thermostat, you can check the continuity of the switch contacts using a multi-meter. If you are doing this for the first time, you may need a wiring diagram to identify which wires and contact terminals to test. If even one contact terminal point is defective, you must change the entire thermostat switch.
How to Recalibrate Your Oven
The oven temperature can be tested by placing an oven-safe thermometer inside and running the oven for about 25 minutes at 300°F. Record the maximum and minimum temperatures of three separate cycles. Add all the recorded temperatures and divide by six to get the average internal temperature.
If the average temperature of the oven is more than 20 degrees off from the setting, you should try to recalibrate the thermostat. Consult your owner’s manual for specific instructions on adjusting the calibration screw or digital offset.
If your oven continues to undercook or overcook food, you may need help resolving oven heating issues. For more appliance repair guidance, visit our main resource page.