Upper oven is completely cold
Lights, display, and fan may work, but the cavity never starts warming.
Start here: Check the cooking mode, timer, and door first, then watch for any sign of the bake element glowing or the igniter trying to light.
Upper oven heat failure
Thermador Double Oven Upper Not Heating
Direct answer: If the lower oven still works but the upper oven stays cold, the most common causes are a wrong cooking mode, a timer or demo-style setting, a bad upper oven bake element on electric models, or a weak upper oven igniter on gas models.
Most likely: Start by confirming the upper cavity is actually calling for bake heat. If it is, the strongest part failures are the upper oven heating element, upper oven igniter, or upper oven temperature sensor.
First separate a no-heat problem from a slow-heat or broil-only problem. That one split saves a lot of wasted time. Reality check: when one oven in a double unit works and the other does not, the house power is usually not the whole story.
Don’t start with: Do not start by ordering an oven control board. Controls do fail, but not nearly as often as a heating part or sensor.
If the upper oven broils but will not bake,focus on the upper oven bake circuit first.
If the upper oven shows preheat but never gets hot,suspect a weak igniter, failed heating element, or bad temperature reading.
Last reviewed: 2026-04-17
What the upper oven is doing tells you where to look first
Upper oven broils but will not bake
The top heat works, but normal baking leaves food raw and the cavity barely warms.
Start here: This points hard toward the upper oven bake element on electric models or the upper oven bake igniter on gas models.
Upper oven heats very slowly
It eventually gets warm, but preheat takes far too long or temperature stalls well below the set point.
Start here: Look for a weak igniter, a partially failed bake element, or a temperature sensor reading off.
Upper oven starts heating, then quits
It may warm for a few minutes, then stop climbing or cycle off too early.
Start here: Check for a loose connection smell, a failing sensor, or a control issue only after the heating part checks out.
Most likely causes
1. Wrong upper oven mode, timer, or delayed start setting
On double ovens, it is easy to have the upper cavity selected wrong or sitting in a timed mode that looks active but never calls for heat.
Quick check: Cancel the cycle, clear any timer or delay setting, choose upper oven bake, and set a temperature well above room temperature.
2. Failed upper oven bake element
On electric ovens, a dead or split bake element is the most common reason the upper oven will not heat or only broils.
Quick check: With power off and the oven cool, look for blistering, cracks, or a burned-through spot on the lower heating element in the upper cavity.
3. Weak or failed upper oven igniter
On gas ovens, a weak igniter may glow but still not pull enough current to open the gas valve, so the oven never lights or heats very slowly.
Quick check: Start bake and watch through the bottom panel area if visible. A glow with no flame after a short wait strongly points to the upper oven igniter.
4. Upper oven temperature sensor reading wrong
If the sensor reads hotter than the cavity really is, the control can cut heat early or refuse to drive the bake circuit long enough.
Quick check: If the oven warms a little but never reaches set temperature and the heating part looks normal, move the sensor higher on the list.
Step-by-step fix
Step 1: Reset the upper oven settings and confirm you are testing the right cavity
A surprising number of double-oven no-heat calls turn out to be a selected-lower-oven mistake, a timer hold, or a mode that is not actually asking for bake heat.
- Cancel any active cycle on both ovens.
- Clear delayed start, cook time, Sabbath-style hold, or timer settings if present.
- Select the upper oven only, choose Bake, and set it to 350°F or higher.
- Close the door fully and wait a few minutes for signs of heat, smell, or normal preheat behavior.
- If the control panel is acting oddly or not accepting commands, stop here and treat it as a control-panel problem instead of a heating problem.
Next move: If the upper oven starts heating normally after a full cancel and restart, the issue was likely a setting or mode problem. If the display accepts the command but the cavity stays cold or barely warms, move on to the heating pattern checks.
What to conclude: You have ruled out the easy user-setting causes before opening anything up.
Stop if:
- The control panel is unresponsive, flickering, or showing obvious error behavior.
- You smell burning plastic or see smoke.
- The breaker trips when you start the upper oven.
Step 2: Separate electric bake-element failure from gas igniter failure
The next move depends on how the upper oven makes heat. Electric models usually fail at the bake element. Gas models often fail at the igniter.
- Turn power off before any close inspection.
- For an electric upper oven, inspect the upper oven bake element for splits, bubbles, heavy pitting, or a burned spot.
- For a gas upper oven, restore power, start Bake, and watch for igniter glow and burner ignition through any visible opening without reaching into the oven.
- Listen for normal relay clicks and watch whether the broil function works while bake does not.
- If broil works but bake does not, keep your focus on the upper oven bake side rather than the whole appliance.
Next move: If you find a visibly damaged upper oven bake element or a glowing igniter that never lights gas, you have a strong repair direction. If there is no visible damage and the behavior is still unclear, check the sensor and heat response next.
What to conclude: Common-wrong-move: replacing the control first because the display looks normal. A normal-looking display does not prove the heating parts are good.
Step 3: Check whether the upper oven is heating a little or not at all
A little heat usually points to a weak igniter, a partially failed element, or a bad temperature reading. No heat at all points more toward an open heating part or a control not sending power.
- Place an oven-safe thermometer in the center of the upper oven if you have one.
- Run the upper oven on Bake for 10 to 15 minutes.
- Note whether the cavity gets warm, whether broil still works, and whether preheat seems to stall.
- On electric models, watch for the upper oven bake element heating during bake. On gas models, listen for ignition and feel for rising heat after the igniter sequence.
- Shut the oven back off and let it cool before touching anything inside.
Next move: If the upper oven gets some heat but cannot climb or hold temperature, the sensor or a weak heating part becomes more likely than a dead control. If there is still no real heat, the bake element or igniter stays at the top of the list, with wiring or control farther behind.
Step 4: Inspect the upper oven temperature sensor and obvious wiring condition
Once the main heating part is not an obvious slam dunk, the next most useful check is whether the upper oven is getting a bad temperature signal or has visible heat damage at the connections.
- Turn power off at the breaker and confirm the oven is cool.
- Locate the upper oven temperature sensor inside the cavity, usually projecting from the rear wall.
- Check that the sensor is straight, secure, and not touching the oven wall or covered in heavy baked-on residue.
- Look for burned wire ends, loose terminals, or heat damage where the upper oven bake element or igniter connects if those areas are accessible without major disassembly.
- If the sensor looks damaged or the wiring is visibly burned, that is enough to justify repair on that branch.
Next move: If you find a damaged sensor or burned connection, repair should focus there instead of guessing at the control. If the sensor and visible wiring look normal and the upper oven still will not heat, the remaining likely causes are a failed heating part you could not fully confirm or an internal control issue.
Step 5: Replace the failed upper-oven heating part, or stop at the control diagnosis line
By now you should have enough evidence to choose a sensible repair path instead of shotgun parts buying.
- Replace the upper oven bake element if it is visibly damaged or the upper oven broils but will not bake on an electric model.
- Replace the upper oven igniter if it glows without lighting gas, lights late, or the upper oven heats very slowly on a gas model.
- Replace the upper oven temperature sensor if the oven heats weakly or cycles wrong and the sensor is visibly damaged or strongly suspected after the earlier checks.
- If none of those fit and the upper oven still will not heat, stop before ordering a control board and have the unit properly diagnosed.
- After any repair, run the upper oven through a full bake preheat and a 20-minute hold to confirm stable heat.
A good result: If the upper oven now reaches and holds temperature, the repair path was correct.
If not: If the new heating part does not restore heat, the problem is likely in wiring, relay output, or another internal control issue that needs deeper testing.
What to conclude: Finish with the part that matches the behavior you actually saw. If the clues do not line up, this is the point to bring in a service tech.
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FAQ
Why does the lower oven work but the upper oven will not heat?
That usually means the problem is local to the upper cavity, not the whole appliance supply. The most common upper-only failures are a bad bake element on electric models, a weak igniter on gas models, or a sensor issue.
Can an oven igniter be bad if it still glows?
Yes. A weak oven igniter can glow and still fail to open the gas valve properly. That is a very common reason a gas oven preheats slowly or never lights on bake.
If broil works, is the control board still bad?
It is possible, but not the first bet. If broil works and bake does not, the bake element, bake igniter, bake wiring, or bake relay path is more likely than a total control failure.
Should I replace the temperature sensor first?
Not usually. Start with the heating pattern. If the upper oven is completely cold, the bake element or igniter is the stronger suspect. The sensor moves up the list when the oven heats a little but reads or cycles wrong.
Can a bad door gasket keep the upper oven from heating?
A bad upper oven door gasket can cause weak performance and long preheat, but it usually does not cause a completely cold oven. Treat it as a secondary issue unless you can see major heat leaking around the door.
Is it safe to keep using the lower oven while the upper oven is broken?
Usually yes, if there is no gas smell, no breaker tripping, no burning odor, and no visible wiring damage. If any of those show up, stop using the appliance until it is repaired.