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9 Ways to Know if Your Oven Temperature Sensor Is Bad

Your oven temperature sensor is bad if you have to deal with problems such as poorly cooked food, the oven failing to reach the desired temperature, shutting off too early or failing to turn on overheating, or uneven baking. Testing or replacing the temperature sensor is important if you’re experiencing any of these issues. The following guide will walk you through the process.

I’ve used a Thermador oven for about six years and had to replace my temperature sensor twice. According to a report from Mordor Intelligence, the Temperature Sensor Market is expected to register a CAGR of 4.6% up to 2027.

So you’re not alone if your oven temperature sensor is faulty now and then. But before you go replacing a sensor that isn’t bad, I’ll show nine simple ways to check that your Oven Temperature sensor is indeed faulty and needs replacement.

Discover dead simple guides on performing thorough sensor checks and replacing a bad temperature sensor if you have to.

How Do You Know If Your Oven Temperature Sensor Is Bad?

Here are nine simple ways to test or confirm if your oven’s temperature sensor is bad:

  • The oven doesn’t reach the desired temperature
  • Food is undercooked
  • The oven turns OFF prematurely
  • The oven doesn’t Turn On
  • Overheating/overcooking issues
  • Uneven baking
  • Temperature fluctuations
  • Sensor’s location (touching the oven wall)
  • Sensor’s electricity

Oven Doesn’t Reach the Desired Temperature

Your oven will never reach the desired temperature if it has a defective temperature sensor. According to Appliance Board Repair, the faulty sensor may regulate the oven’s temperature such that it’s too high or too low, but it’ll never be at the correct value.

The longer the sensor goes without a repair or replacement, the further off it’ll be from the desired temperature. So your oven becomes useless as a result of a faulty sensor.

You can use a separate thermometer to check if the oven reaches the desired temperature. For example, hang a Rubbermaid Instant Read Oven Thermometer inside the oven to monitor its internal temperature. If the sensor turns the oven off, but the thermometer reading doesn’t meet the desired temperature, you have a faulty sensor.

Food isn’t Thoroughly Cooked

Poorly cooked food is evidence of a faulty oven temperature sensor. To confirm that you’re dealing with a bad sensor, use a thermometer to check if the food is thoroughly cooked. You could also cut the food in half to assess if it’s cooked to its core.

How does the sensor affect food?

A broken sensor stops the heating before the oven reaches the ideal temperature required for this food. As a result, the food isn’t cooked to its core.

Keep in mind that other scenarios can also prevent the food from cooking to the core. So while uncooked food could imply a faulty temperature sensor, there are other factors you should consider. We recommend that you test for all the symptoms on this list before you proceed with any fix.

Oven Shuts Off Prematurely

Faulty temperature sensors will cause your oven to shut off prematurely. The sensor sets and regulates the temperature of your oven. A bad sensor can turn off your oven prematurely, bringing down its temperature to a minimum.

However, this symptom doesn’t tie in with the oven’s timer. If the timer beeps too early, it needs to be monitored or replaced. Note that your oven might also shut off early if there’s a loose electrical connection, a broken heating element, or insufficient gas (for gas ovens).

To verify if a faulty temperature sensor specifically causes the premature shut-off, inspect the food you just cooked. Use a thermometer, or cut the food open. Half-cooked or overcooked food both imply a faulty sensor.

NB: Never consume food from an oven that shuts off too early. Instead, remove the food and replace the temperature sensor (we’ll provide a step-by-step guide at the end of the article).

Oven Never Turns On

A broken temperature sensor is one of the leading reasons your oven won’t turn ON. The sensor controls the heat supply to the oven. So a bad sensor could prevent heat from reaching the oven, causing the heating element to stay cold. The outcome is an oven that doesn’t turn ON.

In some cases, your oven will turn on for a moment and then shut off.

Here’s a list of potential reasons why the temperature sensor stops the oven from working:

  • The sensor’s wires are corroded from excess heat, moisture, or calcification. This problem occurs when the sensor is installed incorrectly, exposing it to high temperatures and water in the air. This is a warning to be careful with DIY installations.
  • The temperature sensor isn’t properly connected to the control board. If your oven has a control board, it supplies electricity to all components from a nearby outlet. This simple issue can be fixed by tightening the wires on both ends.
  • The sensor is broken and needs to be replaced. All oven parts will need to be replaced eventually. After a few years, you might have to get a new sensor to return your oven to its original condition.

Food Overcooks Every Time

While broken sensors are commonly known for reducing oven temperatures and causing half-cooked food, some faulty sensors go the other way to cause overcooked food. In addition, such faulty sensors tend to skyrocket desired oven temperatures to extreme levels.

For example, you’ve set your desired temperature to 350 degrees Fahrenheit. Then your broken sensor unwantedly skyrockets the oven temperature to 450 degrees or more. Your food gets constantly overcooked as a result.

Uneven Baking

A broken temperature sensor often causes unevenly baked food. Like the half-cooked food issue discussed earlier, partially baked food clearly shows poorly distributed oven heat.

A faulty sensor will most likely misread the set temperature, so the oven does not heat to the right intensity. With a shortage of heat to circulate the oven evenly, food comes out unevenly baked.

You’ll find food cooked on one side and uncooked on the other. Sometimes people blame food density or placement, but this is rarely true. Instead, we recommend checking your sensors immediately if you see uneven baking. And don’t eat the food.

You can check the temperature sensor with a multimeter to know if it’s the cause of the uneven baking.

Random Oven Temperature Spikes

A working temperature sensor maintains a steady temperature once the oven reaches the correct temperature setting. If your oven’s sensor is faulty, you’ll notice the temperature go up and down randomly. These spikes often occur in 10 to 20-degree increments, but they might not return to the right temperature when done.

Assuming the thermometer works, you can monitor the temperature to see if it’s fluctuating. A properly functioning temperature sensor shouldn’t go up or down once it reaches the right temperature. Instead, the circulation fan and the thermostat ensure it stays at the exact setting.

Emma Christensen (Kitchn) suggests that for temperatures off by more than 100°, you’ll need to call a professional.

The Sensor is Touching the Oven Wall

A temperature sensor that touches the oven wall is a symptom and a cause of oven sensor malfunctions. Here’s how this works:

  • The sensor touching the oven wall is a symptom because the wires and mounting hardware wear down as the sensor ages. The sensor loosens and touches the edge when the wires aren’t connected properly. It can often be fixed by replacing the wires or tightening the mounting hardware.
  • The sensor touching the oven wall is a cause when it’s installed incorrectly. Once the sensor touches the wall, it’ll send false readings to the oven. The high temperature corrodes and melts the sensor. These parts are designed for the ambient temperature, not the extremely high temperature of the walls and grate in the oven.

If your oven temperature sensor is touching the wall, fixing or replacing it as soon as possible is essential. The last thing you want is for the wires to melt and cause a much bigger (and more expensive) problem.

No Power Coming From the Sensor

If your temperature sensor isn’t getting power, it’s faulty and must be replaced. It’s a good idea to test your oven’s components every time there’s a power outage to ensure everything has enough electricity. Fortunately, it’s quite easy to test the temperature sensor.

Use these simple 4-step-process:

  • Turn off the circuit breaker going to the oven. You must turn off the breaker to prevent electrical hazards. Most ovens have 220 volts going to them. Unplug the oven from the outlet to safeguard yourself from residual electricity while working on the oven. You can also wear rubber gloves.
  • Pull the oven out of its slot to reveal the rear panel. The panel should be secured with multiple screws or bolts, so you’ll need a Phillips screwdriver or socket wrench. If your oven is set in a wall, you’ll likely need to remove the faceplate to pull it out. You might also need to remove extra security brackets.
  • Remove the rear panel and locate the temperature sensor. Most sensors are on the top right of the rear panel. It looks like a rod connected to two wires. The sensors are often confused with broil elements, so make sure you differentiate them by looking for the metal rod.
  • Unplug the temperature sensor and test it with a multimeter. The aforementioned wires pull off the sensor easily. Hold the rod with one hand and pull the wires off with the other. Test the rod’s socket (where the wires go) with a multimeter to look for 1,000 to 1,200 Ohms.

If you don’t have one, try the AstroAI Multimeter. It tests for ohms, volts, and so on. Touch the two nodes to the temperature sensor slots where the wires should go. The meter instantly shows if there’s any resistance (ohms) which lets you know if the temperature sensor needs to be replaced. If it reads below 1,000 ohms, you need a new sensor. 

How to Replace Your Oven Temperature Sensor

Follow the steps below to replace your oven’s temperature sensor at home. This is a complete DIY approach, however, we advise getting a professional to look into the issue.

  1. Remove the oven’s rear panel and unplug the temperature sensor from its wires. These wires go to the control panel that supplies the electricity. If the sensor doesn’t show any resistance on the multimeter, it’s not pulling power from the outlet or control board.
  2. Contact the oven’s manufacturer to find the appropriate temperature sensor. There are generic brand sensors, which are unreliable and incompatible with each oven.
  3. Push the temperature sensor through the slot where the old one was. It should press against the pre-existing seal to prevent excess heat from entering the oven’s rear panel.
  4. Plug the wires from the old temperature sensor into the new sensor. They should fit perfectly, letting you seal the rear panel of the oven. Put the screws or bolts back into the panel and slide the oven into its slot, ensuring you plug it into the outlet.
  5. Turn on the circuit breaker and check if the temperature sensor works. Turn on the oven to a mid-range temperature, such as 350 degrees Fahrenheit. Everything should be good to go if it gradually rises and stays at the set temperature.

Fortunately, replacing the temperature sensor is easy and relatively inexpensive.

If you prefer a video tutorial, review this helpful guide by AMRE Supply.

If you are wondering if you can leave your oven on overnight, the answer is yes, but it is never recommended, especially if you leave it unattended. Leaving an oven on overnight is dangerous if you’re asleep and no one watches it. No one will be able to prevent any risk or danger from happening. 

Finally, if your meal needs to be prepared for over 12 hours, never leave it unsupervised. Every oven, whether electric or gas, may be left open if you watch what you’re cooking. To prevent any risk or danger, turn your ovens off after any dish is ready to serve. 

Author

  • Steve Rajeckas

    Steve Rajeckas is an HVAC hobbyist with an avid interest in learning innovative ways to keep rooms, buildings, and everything else at the optimal temperature. When he's not working on new posts for Temperature Master, he can be found reading books or exploring the outdoors.

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