How to Test an Oven Thermostat

Last Updated: August 4, 2021 References

An oven thermostat reads and regulates the temperature inside of your oven. If you want your oven to cook food evenly, it’s critical that the thermostat is working correctly. To test the thermostat, you’ll first need to remove it, then use a multimeter to test it. If you want a quicker and easier, but less accurate test, you can use an oven thermometer to test the temperature of the oven and compare that to the digital readout on the oven itself.

Method 1

Method 1 of 2:

Using a Multimeter

1
Turn off the circuit that powers your oven. Turn off and unplug your oven. Then, find the breaker box and look at the schematic on the circuit breaker door to find the switch that controls the electricity to your oven. Flip the switch to the off position to cut off the power.^{[1]
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- Turning off the power to the oven will prevent you from being electrocuted.
2
Unscrew the back of the oven. Read the user manual that came with your oven and read any warnings or directions that may be in it. To gain access to your thermostat, you’ll need to unscrew the back of your oven. Use a Phillips head screwdriver to remove the screws on the back of the oven. Once all the screws are removed, you should be able to slide the back panel off.^{[2]
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- Screws will usually line the perimeter on the backside of your oven. Remove all of them to remove the back faceplate.
- Set the screws aside in a safe place because you'll need them to screw on the backplate once you're done.
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3
Locate and disconnect the oven thermostat. The oven thermostat will be connected to a rectangular plate that has 2 screws in it and a wire leading to a square plastic plug. This will usually be on the bottom right on the back of the oven. Pull on both ends of the plastic plug to disconnect the wire.^{[3]
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4
Unscrew the back of the thermostat sensor and pull it out. Use a Phillips head screwdriver to remove the screws attaching the thermostat faceplate to the oven and set them aside for later. Once the screws are removed, carefully pull the thermostat out from the hole.^{[4]
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5
Set your multimeter to the ohm setting. Multimeters are used to test and measure electrical current in a circuit and can be used to test whether your thermostat is working. You can purchase a multimeter at a hardware store or online. The ohms setting is a Ω symbol and can be found on most modern multimeters.
- If you have a multimeter that doesn’t have the ohm setting, you’ll need to set it to the 2k or 4k setting.^{[5]
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6
Place the multimeter's probes into each side of the thermostat's plastic plug. Grab the red and black probes on the end of the multimeter and insert them into the plastic terminals in the thermostat's plug. Touch the probes to the round metal contacts inside of the white plastic plug to get your thermostat's ohm reading.^{[6]
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7
Read the ohm reading on your multimeter. A room temperature oven thermostat should have an ohm reading of 1,000 - 1,100. A reading much higher or lower than this is an indication that your oven thermostat is broken or damaged. If this is the case, you should replace your thermostat.^{[7]
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8
Reattach the thermostat when you're done testing it. If you tested your thermostat and it seems to be working, you can reattach it. Slide the thermostat back into its hole and screw it back into the oven. Reattach the plastic plug by pushing both ends back together, then reattach the backside of your oven back into place.^{[8]
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Method 2

Method 2 of 2:

Using an Oven Thermometer

1
Place the thermometer in the center of the oven. You can compare the temperature that you set in your oven with the temperature of the oven thermometer. This will tell you whether the thermostat on your oven is working correctly.^{[9]
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- You can purchase an oven thermometer online or at a kitchen goods store.
2
Set your oven temperature to 350 °F (177 °C). Let the oven preheat completely. As the temperature in the oven rises, your thermometer reading should also increase.^{[10]
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3
Check the temperature of the thermometer. If the temperature is the same as the setting on the oven, then your thermostat is working correctly. If the thermometer doesn't match your oven, it's an indication that it's faulty. You should re-test your oven to make sure that the thermostat is broken.^{[11]
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4
Let the oven cool and repeat the process to get an average. Test the oven 2-3 times to make sure your first test was accurate. If the temperature on the thermometer is consistently different, then the thermostat in your oven is faulty and will need to be recalibrated or replaced altogether.^{[12]
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- Sometimes you can find thermostat recalibration instructions inside of the oven's user manual.
5
Adjust the temperature to compensate for a faulty thermostat. If you can't recalibrate your oven's thermostat, you can manually increase or decrease the temperature setting to get the temperature that you need. For instance, if your oven is regularly 20 °F (−7 °C) lower than what you set, adjust the temperature 20 °F (−7 °C) higher to reach the actual temperature that you want.^{[13]
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- You can double-check whether the temperature is correct with the oven thermometer before you start cooking.