Thermador Gas Stove Burner Won't Ignite: Causes

Quick Answer: Why Your Thermador Gas Burner Won't Light#

Most likely: a failed igniter — it is the most frequently replaced part when a Thermador burner won't light. On the cooktop that is the ceramic spark electrode; in the oven it is the hot-surface igniter that must glow bright (reaching 1800-2500 degrees F) to draw enough current to open the gas safety valve. Behind the igniter, the usual secondary causes are a faulty spark module, clogged burner ports, or a gas valve that won't open. The fastest triage is the click: turn a knob and listen, because whether the burner clicks tells you if the spark module is even firing.

Likely Causes at a Glance#

Walking Through the Diagnosis#

Know where the gas shutoff is before you start, and never test with a match or lighter. Then use the click to split the problem. Turn each cooktop burner to the light position: if none of them click, the shared spark module is the likely fault; if only one fails to click, focus on that burner's electrode and wiring.

For a burner that clicks but won't catch, the cause is usually wet or dirty. Lift off the cap and head, clear each port with a straight pin (a toothpick can snap off and block one), and dry everything thoroughly, since moisture from a boil-over or cleaning shorts the spark. Check the electrode for cracks, carbon, or too wide a gap — it should sit about an eighth of an inch from the burner — and clean a corroded tip with fine sandpaper. For the oven, the hot-surface igniter is the star: it should glow bright orange within thirty to sixty seconds, and a good one reads roughly 40-400 ohms, so anything over 400 ohms is a weak igniter that glows but never draws the current needed to trip the valve open (a healthy draw is about 3.2 to 3.6 amps). Confirm the gas shutoff is fully open (handle parallel to the pipe) and that other gas appliances work, then inspect all wiring for burn marks or loose spade connectors. These are BSH-engineered ranges with the ExtraLow burner (down to 375 BTU) and precision valves, so valve work is a professional job.

How to Prevent This#

Keep the burner ports clean and dry, and reseat caps flat after cleaning, since a tilted cap misdirects gas. Replace an aging oven igniter proactively during service — hot-surface igniters last about three to five years with daily use, while cooktop spark igniters run seven to ten or more.

Repair or Replace? The Short Version#

An igniter or a cleaned port is an inexpensive fix, and even a spark module is a targeted part well below any replace threshold on a range of this quality. The gas valve is the one to leave to a licensed technician, as it involves gas-line work and leak testing. Our technicians carry Thermador igniters and spark modules and confirm the cause first — book a technician.

Frequently Asked Questions#

Why does my Thermador burner click but not light?#

Clicking means the spark module is firing voltage to the electrode, so the usual culprit is a wet or dirty burner shorting the spark. Remove the cap, dry it thoroughly, and clean the ports; if it still won't catch, the electrode gap may be too wide or the electrode cracked.

Can I light the burner with a lighter if the igniter is broken?#

You can manually light a cooktop burner with a long-reach lighter as a temporary measure — knob to low, flame near the ports. Never do this with the oven, though, because its gas valve safety relies on the igniter's current draw; get the igniter fixed promptly.

How long do gas stove igniters last?#

Oven hot-surface igniters typically last three to five years with daily use, while cooktop spark igniters last seven to ten years or more since they are solid-state. Humidity and frequent boil-overs shorten their life.

None of my burners click — what's wrong?#

When no burner clicks, the shared spark module is the likely failure rather than an individual igniter. If only one burner is silent, the fault is that burner's electrode or its wiring instead.