Short answer: A La Cornue burner that will not light is usually a fouled igniter or worn spark electrode; one that lights then goes out points to a thermocouple no longer holding the safety valve open. Cleaning and replacing these restores reliable ignition.
Will Not Light
A burner that will not light usually has a fouled or wet igniter, a worn spark electrode, or a clogged port from spill-over. We clean and dry the igniter, clear the ports, and replace the electrode if the spark is weak, so the burner lights reliably on the first try.
Lights Then Goes Out
A burner that lights but drops out when you release the knob points to the thermocouple, which senses the flame and holds the safety valve open. A weak or failed thermocouple lets the valve close and the flame die. We test and replace it.
Flame Quality
A yellow, lifting, or uneven flame after ignition usually means a clogged port or an incorrectly seated cap rather than an ignition fault. We clean the burner and confirm a crisp blue flame across all ports.
Error & Symptom Reference
| Symptom | Likely Cause | Fix |
|---|---|---|
| Will not light | Fouled igniter/electrode | Clean/replace |
| Lights then dies | Weak thermocouple | Replace thermocouple |
| Yellow/uneven flame | Clogged port/cap | Clean, reseat cap |
| Weak spark | Worn electrode | Replace electrode |
Getting It Diagnosed Right
The reliable move with a La Cornue problem is to confirm the actual cause with a meter before any part gets replaced. We work through the likely causes in order, so you pay to fix the real problem on your La Cornue unit, not a list of guesses. It helps to record whether the problem happens cold, mid-cycle, or under load, since the timing points to different parts. If you would rather not chase this down yourself, we handle these repairs across Greenwood Village and the surrounding area with a written estimate up front.
Want This Handled for You?
Book a diagnosis. Diagnostic and travel fees, if applicable, are confirmed before the appointment and before repair approval.