Thermador Stove Repair in Toronto — Gas burner clicks but won't light

• The Thermador Pro Star burner lights from a dedicated spark electrode, and the part Thermador itself catalogues for it is 00415124 (Electrode, Spark For Pro Star Burner). When one ring clicks but never lights while its neighbours fire fine, the fault is almost always that single electrode: a hairline crack in the ceramic shield bleeds the spark to the burner body, so the arc never jumps the gap to the gas. We inspect the ceramic for crazing and meter the spark path before condemning it — a cracked 00415124 reads as a healthy click but a dead light-off.
• On the conventional (non-star) surface burners and on Bosch-built Thermador cooktops, the equivalent electrode is 00189324, which Thermador/Bosch supersedes from the older 189719, 189889, 413966, 488832 and 189733 numbers, while 00418885 (Ignition device, Spark, 'Bake Pro') covers other surface-burner fitments. Getting the right one is a model/serial question, not a guess — carrying the wrong supersession is the most common reason a 'won't light' call needs a second visit, so we look up the exact electrode against the serial before the truck rolls.
• When the click is missing entirely on one burner (no spark at all, gas you can smell but no tick), the suspect shifts from the electrode to the per-knob spark-ignition switch — Thermador 00189819. That switch closes when the knob hits the 'Lite' position and feeds the spark module; a worn contact means no spark command reaches the electrode. We test the switch closure on the suspect knob versus a known-good burner, because a dead switch and a dead electrode present identically as 'this one burner won't light.'
• When EVERY burner clicks but none light (or the whole top clicks with the knobs off), the fault is upstream of any single electrode — it is the central re-ignition spark module/generator (Bosch/Thermador 00753257, the 4/5/6-point module fixing kit; older cooktops carry 00618624) or a shared wiring/ground fault, not five failed electrodes. We test for the all-burners-tick signature first and confirm the exact module against the model/serial; condemning individual 00415124/00189324 electrodes on a whole-top complaint is a classic misdiagnosis we avoid by checking the module and its ground before ordering any electrode.
• Moisture and boil-over residue are the honest no-charge fix on this symptom: a spill that soaks the star burner cap or the spark switch makes the electrode arc to the wet metal instead of the gas, so it clicks without lighting. Thermador's own troubleshooting calls for drying the igniter and clearing the burner ports before any part. We dry the spark switch and electrode, clear the star-burner port ring with a wire, and re-seat the cap square on its locating pins before we'll sell a 00415124 — a misaligned or wet star cap mimics a dead electrode exactly.
• A burner that clicks AND sparks visibly but still won't catch is a gas-delivery fault, not an ignition fault: a clogged star-burner orifice or a valve not opening (the documented PRG304-class 'gas does not flow to the burner' pattern). Replacing electrodes here fixes nothing — we confirm spark is present, then chase the orifice and valve, because the spark side of a no-light call is innocent once a strong blue arc is visible at the gap.
• On Pro Grand and Pro Harmony models the oven side has its own ignition path — the glow-bar oven igniter 00415504 (Bosch; cross-referenced 414136, 1013977 and 35-00-190). When the cooktop lights fine but the gas oven won't, the weak glow-bar can no longer draw enough current through the safety valve to open it, so the igniter glows but gas never releases. We meter the igniter for continuity and amperage draw; a glow that doesn't open the valve is the 00415504 failing under load, and it is a different part and diagnosis from any rangetop electrode.

Thermador gas burner clicks but won't light in Toronto — the local specifics

• The recurring Toronto pattern on Thermador 'gas burner won't light' calls is the single-ring complaint on a Pro star top — one burner clicking without catching while the rest fire — which resolves to a cracked 00415124 star electrode or a worn 00189819 spark-ignition switch far more often than to anything central. The second recurring pattern is post-boil-over: a soaked star cap or spark switch that dries out and works again, so we always rule out moisture and cap alignment before quoting a part.
• We carry the high-turn ignition parts to these calls: 00415124 star-burner spark electrodes, 00189324 surface electrodes (with the common supersessions), 00189819 spark-ignition switches, and for Pro Grand oven no-light follow-ups the 00415504 glow-bar igniter — plus a meter and port-clearing tools so a wet-cap or clogged-orifice no-light gets fixed without an unnecessary part swap.

For the full Thermador stove module — every fault, part number and code — see Thermador stove repair in Toronto, and for the same fault across all brands the stove gas burner clicks but won't light guide.