Because most La Cornue ranges are mechanical, the flame is the first thing a Houston owner can read for free. A healthy burner shows a steady blue cone, evenly spaced around the cap, with no lifting and no yellow tips.
What each flame tells you
- Yellow tips or a lazy, orange flame: the gas and air mix is off, or the ports are fouled with boil-over residue.
- Flame lifting away from the ports: too much gas pressure or air for that burner, or a mismatch with the fuel type.
- One side missing: a blocked port or a cap that is not seated in its base.
- Flame that pops out at low setting: a draft, a dirty low-flame passage, or a worn valve.
What you can check yourself
Turn the burner off and let it cool. Lift the cap, look for crust in the ports, and set the cap back so it sits flat and cannot rock. Use a soft brush or a wooden toothpick, never a metal pin that enlarges a port. Then relight and compare against the list above.
What the flame cannot tell you
Color alone does not separate a dirty cap from a regulator or fuel-type problem. If every burner looks wrong the same way, cleaning will not fix it, and the cause sits upstream in the gas supply or the regulator.
Keeping a simple log
Note the date, which burner, and what the flame looked like when something changes. A short record turns a vague memory into a pattern, and the pattern often shows whether the cause is a single cap, a whole bank of burners, or the supply. Photos taken in a dim kitchen show flame color better than the eye does.
Nothing here replaces a pressure reading, but a few weeks of notes make that reading far more useful. When a pattern repeats on one burner only, the cause is almost always local to that burner.
If one burner stays wrong after cleaning, or all of them do, we measure supply pressure and inspect the valve and cap. See our La Cornue range repair page or check the areas we cover in Houston.