The short answer: a Thermador oven that won't heat usually comes down to a weak or failed igniter (on gas ovens), a failed bake or broil element (on electric ovens), a temperature sensor that has drifted out of calibration, or a control board fault. Thermador ovens are built for long service, so a no-heat fault is almost always a single repairable component.
The most common reasons a Thermador oven won't heat
On Thermador gas ovens, the igniter both lights the gas and signals the safety valve to open. As it weakens with age it glows but can't draw enough current to open the valve, so the oven glows or clicks but never heats. This is the most common Thermador gas-oven no-heat cause and a standard replacement.
On electric Thermador ovens, a bake or broil element that has burned through or lost continuity won't heat. Visible damage is an easy diagnosis; an element that looks intact but tests open also needs replacement.
Thermador ovens regulate heat with a temperature sensor. When it drifts out of spec, the oven underheats, overheats, or never reaches the set temperature. Testing and replacing the sensor restores accurate control — a common fix when the oven 'works' but the temperature is wrong.
The control board switches power to the heating components. A failed relay or board fault can prevent heating even when the element, igniter, and sensor are good. Diagnosis confirms the board is the cause before replacement.
If the Thermador cooktop Star Burners work but the oven won't heat, the problem is isolated to the oven's igniter, element, sensor, or control — not the gas supply. Confirming which part of the appliance fails narrows the diagnosis quickly.
What you can safely check yourself
- Confirm the symptom: Note whether a gas oven glows/clicks but won't light (igniter/valve), or there's no response (element or control).
- Inspect the element (electric): Look for blistering, breaks, or burn marks on the bake/broil element.
- Rule out settings: Check for Sabbath mode, delay-start, or a lockout that blocks heating.
- Check the cooktop separately: If Star Burners light but the oven won't heat, the fault is in the oven circuit, not the gas supply.
- Stop retrying a gas oven: Repeated failed ignition releases unburned gas — if it won't light, stop and call a technician.
SAVA repairs Thermador gas and electric ovens and ranges throughout Chicago and the suburbs — igniters, elements, temperature sensors, and control boards. We diagnose the exact cause and carry common Thermador parts.
📞 (773) 558-3332Common Questions
Why is my Thermador oven not heating?
The most common causes are a weak or failed igniter (gas ovens), a failed bake or broil element (electric ovens), a drifted temperature sensor, or a control board fault. On gas ovens, a weak igniter that glows but won't open the gas valve is the leading cause.
Why does my Thermador gas oven glow but not light?
That's a weakening igniter. It still glows but no longer draws enough current to open the safety gas valve, so the oven never heats. The igniter needs replacement, and because it involves the gas system it's a technician repair.
Why won't my Thermador oven reach temperature?
Usually a drifted temperature sensor or a weakening element. The oven appears to work but underheats or never reaches the target temperature. Testing the sensor and element shows which is off.
My Thermador cooktop works but the oven won't heat — why?
If the Star Burners light but the oven won't heat, the fault is isolated to the oven's igniter, element, sensor, or control — not the gas supply. That actually narrows the diagnosis considerably.
Is it worth repairing a Thermador oven?
Almost always, yes. Thermador ovens are premium appliances built for long service, and no-heat faults are typically a single repairable component at a fraction of replacement cost.
Do you repair Thermador ovens in Chicago?
Yes. SAVA repairs Thermador gas and electric ovens, ranges, and cooktops throughout Chicago and the North Shore — igniters, elements, temperature sensors, and control boards. Same-day service is often available.