La Cornue Cooktop Repair

A burner that lights but goes out the moment you let go of the knob is the La Cornue cooktop call we get most. Many configurations protect each gas burner with a thermocouple flame-safety device, which holds the valve open only while it senses heat. As the thermocouple ages, or if its tip is bent away from the flame, it stops producing enough signal and the burner drops out.

What else can fail depends on the modules chosen when the range was ordered. Besides standard and high-output gas burners, a La Cornue top may include a French top, a solid cast-iron plate heated by a central burner so the middle runs hottest and the edges gentler. Others carry a plancha for searing, an induction zone or a simmer plate. Separate rangetops for countertop installation use the same modules.

A French top is heavy iron and never quick, but one that is far slower than it used to be, or heats unevenly, usually has a dirty or poorly adjusted burner underneath. Planchas depend on their own burner and controls. Induction zones are tested electrically, and failures there tend to sit in the coil or the control board. Spark igniters and switches wear, and spills cause nonstop clicking.

With everything off and cool, clean the burner caps and heads, dry them fully and seat them correctly, and check that each thermocouple tip is clean and sitting close to its flame. Never hold a knob in for long to force a burner to stay lit, and never try to defeat the safety device. If there is any gas smell, leave and call the gas utility or 911 from outside.

We identify each module, then test thermocouples, igniters, switches and valves and check the flame. These parts are replaceable and the range is built to last for decades, so cooktop repair is worth doing. Parts can take a while to arrive, and if only one burner is affected and there is no leak, we tell you which other modules are safe to use while you wait.