How to Fix a Thermador Oven Not Heating

An oven’s only job is to cook your food, so if your Thermador oven isn’t heating, it can be pretty frustrating! Although this might sound like a serious malfunction that needs the attention of a professional, hold on before you make the call. There are actually quite a few DIY fixes you can try if your Thermador oven isn’t heating—read on to find out how. 

This guide applies to all popular models of Thermador ovens, including:

CV2136PB

GPS364GLS

PCS366

PRG304US

PRG366

PRG366US

PRSE484GGS

PRSG366S

RDDS30V

SGC365RS

SGCS304RS

SGCS365RB

SGCS365RS

TMH36GS

TMH45

WDF30DB

WDF30DP

WDF30DS

WDF36DP

WDF36DS

WDF36EP/02

Reset the oven

First things first, if your Thermador oven isn’t heating up, try resetting it. This is a great first step when encountering any appliance issues, as it can help to clear glitches and errors caused by unexpected power surges. The process is simple; just follow these steps:

• Disconnect your oven from its power source. The easiest way to do this is to flip the corresponding circuit breaker to the “off” position. Most ovens are hardwired, so they can’t just be unplugged like other appliances!
• Once your oven is cut off from the power, wait for two full minutes to allow the electricity to fully discharge. 
• Reconnect your oven to the flower by flipping the circuit breaker to the “on” position. 
• Try heating your oven again to about 450° F. If it easily achieves this temperature, the issue is fixed. If it struggles, move on to the next step in this guide. 

Check the temperature sensor

The next step should be to check your oven’s temperature sensor, which detects the oven’s internal temperature, but if it’s faulty or obstructed by grime, it can cause issues. If the sensor isn’t working properly, it may detect that the oven has reached the desired temperature when it actually hasn’t, which will prompt the heating elements to shut off prematurely. To check:

• First, inspect the temperature sensor for dirt or grime. A build-up of debris can prevent the sensor from working properly, causing heating issues. The temperature sensor should be located on the back interior wall of your oven and look like a tapered metal rod. If you’re having problems finding it, check your Thermador manual for help locating it in your model. 
• Inspect the sensor for cleanliness. To work optimally, it should be shiny and clean—any black buildup can hinder its function. 
• Clean the sensor thoroughly with a mild detergent. If there is stubborn grime, make a paste of water and baking soda and wait about half an hour before wiping it off. 
• Once the sensor is clean, try heating the oven again to see if the issues are fixed. 

If cleaning the temperature sensor didn’t work, it might need to be completely replaced. 

• Test the temperature sensor’s functionality with a multimeter. At room temperature, it should read about 1080 ohms. If the number is far outside this range, the sensor is faulty and needs to be replaced. 
• Source a replacement temperature sensor from an appliance parts store. 
• Ensuring the oven is turned off, remove the faulty sensor and put the new one in its place. 
• Try heating the oven again to see if the problem has been fixed. 

Check the bake and broil elements

If you don’t have a sensor issue, the problem may lie with the heating elements. Electric ovens have a bake element (at the bottom) and a broil element (at the top), and if either is malfunctioning, your oven won’t heat properly. If you’ve noticed your oven is heating far slower than usual or your food has been cooking unevenly, then this is likely your problem. 

• Disconnect your oven from the power source. 
• Inspect the elements for visible damage, like cracking or scorch marks. These indicate the elements need to be replaced. 
• Disconnect both elements from their wiring connections, then test their continuity with your multimeter. At room temperature, they should read between 19 and 115 ohms; anything outside this range indicates a fault. 
• If you discover one or both elements are faulty, source replacement parts from an appliance parts retailer, then replace the faulty ones. 
• Once the new elements are installed, restore power and run a test cycle to see if the oven is now heating properly. 

Inspect the igniter

If you have a gas version of a Thermador oven, the causes of heating issues can be slightly different. A faulty gas igniter will prevent your gas oven from lighting, which means it won’t be able to heat up. If  your gas oven stays completely cold when turned on, this is likely to be your problem—here’s how to check:

• Open your oven and locate the ignitor (consult your manual if you’re not sure where it is).
• Watch carefully to see what happens when you try to ignite your oven. If it doesn’t light the gas after repeated tries, it means it is faulty and needs to be replaced. 
• If you can see a spark, but nothing is happening, hold off on replacing the ignitor. You could have a gas supply issue instead! To find out, read our next section.

Check the gas supply

If your gas supply is interrupted or compromised, your Thermador oven won’t be able to heat. To check this:

• Test to see if any part of your Thermador oven is working. If the burners are still lighting, you likely have an issue with your oven ignitor, not the gas supply.
• If no part of the oven will light, you likely have a gas supply issue. Make sure the gas line is turned on.
• Contact your gas supplier to see if there has been an interruption to the gas supply in your area. 
• If the problem persists, call a professional. Working with gas lines can be dangerous and should not be attempted by a DIYer.