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9 Ways to Know if Your Oven Temperature Sensor is Bad

Oven temperature sensors are responsible for setting, adjusting, and reading the internal temperature. Without these handy devices, your oven wouldn’t work properly. They tend to wear down over time, which is why you should know how to diagnose a faulty sensor.

To know if your oven temperature sensor is bad:

  • Check if the temperature is adjusting
  • Inspect the food quality
  • Ensure it doesn’t turn off early
  • Check if it turns on
  • Monitor overheating issues
  • Look for uneven baking
  • Review temperature fluctuations
  • Check the sensor’s location
  • Test the sensor’s electricity

Throughout this article, we’ll discuss the primary reasons an oven’s temperature sensor stops working, what you should look out for, and how to prevent it from happening. We’ll also show you how to test and replace the sensor.

Oven Never Reaches Desired Temperature

If your oven’s temperature sensor isn’t working, it’ll never reach the desired temperature. According to Appliance Board Repair, the sensor can go too high or too low, but it’ll never be at the right setting. This common issue occurs because the sensor thinks it’s reaching the proper setting, even if it’s far off.

You might notice the temperature sensor takes a while to wear down. For example, it might not reach a higher temperature, but it’ll hit lower settings. The longer the sensor goes without being repaired or replaced, the further off it’ll be from the desired temperature. It renders the oven useless since it can’t hit the right setting.

The good news is that you can use a separate thermometer to test if the sensor isn’t working. The Rubbermaid Instant Read Oven Thermometer hangs inside of the oven, letting you monitor the internal temperature. If the sensor turns off the oven and the thermometer isn’t at the proper temperature, you know something’s wrong with the sensor.

Food Isn’t Cooked Thoroughly

If you think the sensor is broken, but you’re unsure, check the food with a thermometer. Another suggestion is to cut the food in half to check if it’s cooked to the core. Some foods, such as chicken or cake, have to be cooked thoroughly to prevent foodborne illnesses. A broken sensor stops heating too early or late, which directly influences how well the food is cooked.

It’s important to keep in mind that a few other scenarios can prevent the food from baking to the core. Here’s a list of potential causes:

  • Changing the oven rack’s height affects how quickly and thoroughly it cooks.
  • The time is equally as important as the oven temperature.
  • The thickness and density of the food change how well it bakes or cooks.

If you set a thick piece of chicken on the lowest rack and a high temperature, it’ll bake to the core at a different rate than a thin piece of quick at a lower temperature and higher rack.

Oven Shuts Off Too Early

Some temperature sensors show signs of failure when they shut off before they should. You turn on the oven, the temperature climbs, then suddenly stops. If the oven isn’t at the correct temperature, the sensor likely needs to be repaired or replaced. The sensors are so inexpensive that most people prefer to replace them.

Keep in mind that this symptom doesn’t correspond with the oven’s timer. If the timer beeps too early, it needs to be monitored or replaced. The oven also might shut off early if there’s a loose electrical connection, broken heating element, or not enough gas (for gas ovens).

If you think the oven turned off too early because of a faulty temperature sensor, check the temperature with a thermometer or inspect the food. Never consume food that’s in an oven that shuts off too early. Instead, follow these steps:

  1. Turn off the oven.
  2. Turn it back on and set the temperature to the desired setting.
  3. Put the food in the oven and stay nearby to ensure the temperature rises.
  4. If the oven’s thermostat shuts off, remove the food and replace the temperature sensor (we’ll provide a step-by-step guide at the end of the article).

It Never Turns On

While there are countless reasons your oven won’t turn on, one of them is that the temperature sensor is broken. If the sensor is broken, the oven won’t know when it’s time to supply heat. The heating element would stay cold, and you wouldn’t be able to use the appliance. In some cases, the oven will turn on for a moment and then shut off.

Here’s a list of potential reasons 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.
  • The temperature sensor isn’t properly connected to the control board. If your oven has a control board, it supplies electricity to all of the 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 handful of years, you might have to get a new sensor to bring your oven back to its original condition.

The Food Overheats Every Time

While most temperature sensors go out by showing reduced temperatures, some of them go the opposite direction. Setting your oven to 350 degrees Fahrenheit skyrockets the oven to 450 degrees or more. The oven could go to its max setting, causing numerous problems. For example, the food will be overcooked and inedible.

If your oven is going to a higher temperature than you set it, it’s almost always the temperature sensor’s fault. Very rarely do the membrane buttons overlap, though it’s worth checking. You can remove the membrane layer over the buttons on a digital oven to check if they’re in the proper place. However, the sensor is likely the issue.

Uneven Cooking and Baking

Den Residence explains a broken temperature sensor often leaves portions of the food uncooked. Much like the aforementioned uncooked core issue, your food will have parts of it that aren’t prepared to eat. The uneven cooking heats part of the oven without providing enough heat for the circulation fan to move around.

You might notice some of the food is completely cooked on the bottom but not the top. It could even cook through some pieces of food and not others. Unfortunately, people often consume these signs with food density, placement, and other examples mentioned earlier in the post.

Uneven baking and cooking is often an early sign of a thermostat or temperature sensor that’s worn down. It can happen a few times before the oven begins to shut off each time you use it. You can check the sensor with a multimeter to know if it’s the cause of the uneven baking.

Random Oven Temperature Spikes

The sensor does its best to maintain a steady temperature once it reaches the correct setting. When it’s broken or damaged, you’ll notice the temperature goes up and down randomly. These spikes often occur in 10 to 20-degree increments, but they might not go back to the right temperature when they’re done.

Assuming the thermometer is working, you can keep an eye on 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. The circulation fan combined with the thermostat ensures it stays at the exact setting.

The Sensor Is Touching the Oven Wall

A temperature sensor that touches the oven wall is a symptom and a cause. 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 gets old. When the wires aren’t connected properly, the sensor loosens and touches the edge. 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 grates in the oven.

If your oven temperature sensor is touching the wall, it’s essential to fix or replace it as soon as possible. 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 doesn’t have power going to it, but the rest of the oven is fine, then it’s broken and needs to 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.

Try this process:

  1. Turn off the circuit breaker going to the oven. It’s crucial that you 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.
  2. 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.
  3. 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.
  4. Unplug the temperature sensor and test it with a multimeter. The aforementioned wires pull off of 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’s Temperature Sensor

To replace your oven’s temperature sensor:

  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, but they’re unreliable and aren’t always compatible 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 coming through 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 that 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. If it gradually rises and stays at the set temperature, everything should be good to go.

Thankfully, replacing the temperature sensor is quite easy and relatively inexpensive.

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