Thermador cooktop smells like gas: stop using it and get the leak checked

Use only checks that match the exact appliance or system and its official guide.

1. Leave before investigating the smell

   If you smell gas around the Thermador cooktop, especially if the smell is strong, persistent, returns after ignition, or comes with hissing, stop using the cooktop and leave the building with people and pets. Do not operate electrical switches, appliance controls, lights, fans, phones, matches, lighters, or vehicle ignition while in the odor area.

   Expected result: From outside, note only safe facts you already observed: odor before ignition or after ignition, whether it persisted, any hissing, and whether the odor was near the cooktop or throughout the building. Do not go back in to confirm the location.

   Next step: From a safe location, call 911 or the local gas utility's emergency service and explain that a gas odor is suspected at a Thermador cooktop. Follow their instructions and wait for an all-clear before returning.

   Stop if: Do not re-enter, search for the leak, close or adjust a valve, unplug equipment, ring a doorbell, or try to extinguish a gas fire; wait for trained emergency or gas personnel.

   Why this matters

   Why: A suspected gas leak can ignite from a spark and cannot be safely localized by a homeowner. The smell pattern does not make it safe to re-enter or perform a burner test.

2. Use the ignition timing only as a service clue

   After the gas utility or emergency professional has cleared the area, write down whether the odor was present before a burner was lit, lasted beyond the brief ignition period, returned between uses, or occurred with every burner; do not relight the cooktop to reproduce it.

   Expected result: The record should say one of: odor before ignition, odor that continued after ignition, odor that returned when the cooktop was off, a brief odor that cleared, or timing unknown.

   Next step: Give the timing record to the gas utility and qualified Thermador servicer. Keep the cooktop out of service until they determine why the odor occurred and explicitly clear it for use.

   Stop if: Do not repeat ignition, hold a knob open to observe the flame, sniff a connection closely, or use a match, lighter, flame, leak detector, or homemade test while troubleshooting.

   Why this matters

   Why: Thermador says a smell for up to about four seconds after ignition may be normal, but a smell that does not disappear requires the gas supply and a service visit. A persistent or off-state odor cannot be classified as normal ignition odor.

3. Check only the cool, visible burner arrangement

   Only after the area is declared safe and the cooktop is completely cool, verify visually that every knob is in OFF and that each burner cap is seated with its tabs aligned with the burner-base notches; do not open the cooktop or disturb gas connections.

   Expected result: Record whether a knob was not fully off, a cap was visibly out of alignment, the caps and knobs appear normal, or the appliance is still warm or inaccessible.

   Next step: If a cool cap is visibly misaligned, provide the model and photos to the qualified servicer or follow the exact owner guidance after the all-clear; if the odor returns or the arrangement looks normal, keep the cooktop off and request service.

   Stop if: Do not adjust a regulator, remove burner bases, disconnect tubing, force a cap, open the appliance, or continue if any gas odor is present.

   Why this matters

   Why: Thermador identifies incomplete knob shutoff and misaligned caps as possible contributors, but a normal visual arrangement does not prove the appliance or supply is leak-free.

4. Prepare a safe handoff to the gas professional

   Collect the cooktop model and installation information from paperwork or a location that can be accessed safely, plus the odor timing, affected burner if known, knob/cap observations, recent cleaning or installation work, and the all-clear or findings supplied by the gas utility.

   Expected result: Confirm whether the odor was isolated to the cooktop, present elsewhere in the building, associated with a recent installation or service, or not safely attributable to one appliance.

   Next step: Request an authorized Thermador service visit or another appropriately qualified gas-appliance professional. Tell them that the appliance has an unresolved gas-odor report and remains unused.

   Stop if: Do not remove panels, test pressure, adjust the regulator, disconnect a flex connector, or perform combustion or leak testing yourself.

   Why this matters

   Why: The same symptom can involve the cooktop, its installation, the building supply, or another gas appliance. The record helps the professional choose the correct gas-supply and appliance-safety assessment without asking the homeowner to dismantle anything.

5. Return the cooktop to use only after qualified clearance

   Keep the Thermador cooktop off until the gas utility or qualified gas-appliance professional has assessed the condition, completed any required repair, and told you that it is safe to use; do not treat a temporarily absent smell as a repair.

   Expected result: The service record should identify what was inspected or repaired, whether the gas supply and appliance were cleared, and what operating restrictions or follow-up apply.

   Next step: Follow the professional's written operating instructions and monitor only during normal use. If any gas odor, abnormal flame, hissing, or ignition problem returns, stop using the cooktop and repeat the emergency branch.

   Stop if: Do not resume use after a self-made adjustment, a reset, or a successful relight alone; stop for any returning odor, unstable flame, damage, or concern about carbon monoxide or ventilation.

   Why this matters

   Why: A gas odor that fades can still have an intermittent or concealed cause. A qualified clearance is the decision boundary; a brief smell-free interval is not proof of safety.