Thermador Oven Not Heating? Here’s What to Do

Whether your Thermador oven isn’t getting hot enough, is heating unevenly, or isn’t heating at all, it can seriously disrupt your ability to cook food properly and safely.

You may have even had to limit yourself to using only the stovetop or microwave in the meantime until the issue is fixed, leaving you longing for the usual delicious roasted and baked foods.

To help you get out of this unappetizing situation, this guide will cover the most common causes of a Thermador oven not heating properly and provide troubleshooting tips to resolve the issue.

Here’s what to do if your Thermador oven is not heating:

1. Check for power issues

If your Thermador oven was heating fine before but suddenly stopped heating properly, it’s unlikely to be a power supply issue. The culprit is more likely to be a faulty component, such as the heating element or igniter, unless the circuit breaker has tripped, but that would result in the oven not turning on at all.

That said, it’s still worth checking the following power supply issues, especially if your oven is newly installed:

1. Check the oven’s dedicated circuit breaker hasn’t tripped.
2. Ensure it’s plugged into a 220-240 volt wall outlet, not a standard outlet.
3. Test the outlet with a multimeter to ensure it’s delivering the proper voltage.

2. Check the heating elements (electric models)

If you have an electric Thermador oven, the heating elements are the primary heat-producing components. Therefore, if your oven is no longer heating properly, these elements are among the most likely problems and the first parts to check.

Most Thermador ovens have two or three heating elements, including:

1. Bake element.
2. Broil element.
3. Convection bake element.

Each is located in a different area within the oven. You can check that each is working by following these steps:

1. Run your oven on bake mode at a high temperature for a few minutes. Then, open the door and, without touching, carefully check if you can feel any heat coming from the bottom of the cavity. If not, the bake element is likely faulty.
2. Run your oven on broil mode for a few minutes. Then, open the door and, without touching, carefully check if the heating element at the top of the cavity is glowing red and radiating heat.
3. Run your oven on convection bake mode for a few minutes. Then, open the door and, without touching, carefully check if you can see or hear the fan spinning and feel heat radiating from the back wall of the cavity.

If any of the heating elements seem not to be working properly, it’s usually best to call in a professional to replace it. However, those with good DIY skills may be able to replace an oven heating element themselves.

If you find that food is cooking unevenly, or the oven is getting warm but not as hot as it should, it could be that one of the heating elements is working partially. To determine if this is the case, you would need to remove the heating element, inspect it for visible signs of damage, such as blistering or cracks, and test it with a multimeter.

3. Check the igniter (gas models)

One of the most common causes of a gas Thermador oven not heating up is a faulty igniter. To determine if this is the case, you can take the following steps:

1. Turn off the gas and power to your oven.
2. Locate the two gas igniters (bake and broil), usually found at the top and bottom of the oven cavity.
3. Check whether they are covered in dirt and grime. If so, gently clean them with a cloth or soft brush.
4. If an igniter is cracked or looks damaged, it will need replacing.
5. Turn the power and gas to your oven back on, ensuring the gas supply valve is fully open.
6. Run the oven on bake mode and observe if the igniter quickly glows bright orange and ignites the gas.
7. Repeat this process in broil mode.

If either of the igniters does not work, or if they ignite the gas but produce a weak flame, call a gas-certified professional to inspect and repair your appliance. Do not attempt to carry out gas-related repairs yourself.

4. Check the temperature sensor

The temperature sensor monitors and regulates the oven’s temperature. It sends signals to the control board to cycle the heat off and on so the desired temperature is maintained.

When faulty, the temperature sensor can send incorrect signals, leading to the oven heating incorrectly or not heating at all. Testing and replacing a faulty thermostat on a Thermador oven is a job you can carry out yourself. Here’s how:

1. Unplug your oven.
2. Locate the temperature sensor. It looks like a thin metal rod, usually protruding through the back panel of the oven cavity.
3. Remove the screws securing it to the back panel.
4. Pull out the temperature sensor until its wiring harness is revealed. Disconnect it from its wiring harness.
5. Use a multimeter set to ohms to test the sensor’s resistance.
6. At room temperature, you should get a reading of around 1000 to 1100 ohms. If it deviates from this, replace the sensor with a new one.
7. Use a heat gun or hair dryer to apply heat to the sensor. The reading on the multimeter should increase as a result. If it doesn’t increase, replace the sensor.

Other possible causes

The causes we’ve outlined above are the most likely. However, if checking these has not resolved the problem, you could also try the following:

• Check if the thermal fuse has blown and replace it if necessary.
• Ensure the door is closing fully and not allowing heat to escape.
• Have a professional check if the control board is defective.
• Hire a professional to inspect your oven and diagnose the cause of the problem.