La Cornue induction terms come down to a handful of words that you will see on the cooktop, in the manual and on our code pages: pan detection, ferrous cookware, zone, power level, residual heat, the generator, and the symbols H, U and E2. This glossary of La Cornue induction terms defines each one in plain language, says whether it is normal or a fault, and points you to the guide that explains what to do next.
What does induction mean on a La Cornue range?
Induction cooking heats the pan, not the glass. A coil beneath the surface creates a magnetic field, the field induces electric currents in the base of a suitable pan, and the pan’s own resistance turns them into heat. The glass warms second-hand from the pan. That is why induction responds so quickly to a change in power: the heat is made in the pan itself, not transferred from a hot element. Our guide on how La Cornue induction cooking works explains the process in more detail.
La Cornue offers induction in several forms, including Château rangetops, induction ranges and Cornufé cooktops, so the terms below apply across the line. If you are still choosing between gas, dual-fuel and induction, read our comparison of the three.
What is ferrous cookware, and why does it matter?
Ferrous cookware is any pan made of, or containing, a magnetic metal such as iron or magnetic stainless steel. Induction can only heat a pan that responds to a magnetic field, so a pan that a magnet will not stick to will not heat. Copper, aluminum and glass pans do not work unless they have a magnetic layer bonded to the base. The simple test is a refrigerator magnet: if it clings firmly to the bottom of the pan, the pan will work. Our guide to the best cookware for La Cornue induction covers the choices.
What is pan detection, and what does a flashing U mean?
Pan detection is the control’s check that a suitable pan is sitting on the zone before it sends power. If it does not find one, the zone stays off, and on a La Cornue induction top the U flashes over that zone. That is the control saying it cannot see suitable cookware: the pan is the wrong material, too small for the zone, badly warped, or not centered. It is not a fault in the cooktop. Try a pan that passes the magnet test, center it on the zone and check that its base is flat. Our guide to a flashing U on one induction zone shows what to do if one zone keeps doing it while the others work.
What is a zone, and how do power levels work?
A zone is the circle or outline on the glass where a coil sits, and each one is controlled separately. A power level is the amount of electrical power the control sends to the coil, usually shown as a number or a bar on the display. Higher levels send more power, and the control switches the coil on and off rapidly to hold a lower level. Because induction responds almost instantly, a low setting simmers cleanly, and a high setting boils water very fast. A pan that is much smaller than the zone heats less efficiently, so match the pan to the zone where you can.
What does H mean on a La Cornue induction cooktop?
H stands for residual heat. It appears over a zone that has been switched off but where the glass is still hot enough to burn, even though nothing on the surface looks hot. It is a warning, not a fault, and it clears by itself as the glass cools. A heavy pan held at a high setting can keep a zone hot for many minutes after it comes off. Do not wipe the glass while H is showing. Our guide to the La Cornue residual heat indicator explains how long it lasts and why it can appear on a zone you never turned on.
What are E2 and U400, and are they serious?
Both are error indicators, and both deserve attention. E2 is an overheating code: the generator or a zone has run too hot, usually from a pan that boiled dry or from blocked ventilation under the cooktop. Our guide to La Cornue induction E2 overheating covers what to do. U400 is a connection error between the control and the induction generator, and it often appears on a newly installed range because of supply or wiring. See how to avoid U400 with correct induction wiring for the reasons. Do not attempt to open the cooktop to investigate either, because the electronics carry mains voltage.
What is the generator, and why does it matter for repair?
The generator is the electronic module that creates the high-frequency current feeding the coils. It is the most complex part of an induction cooktop and the one that overheats, trips or fails when the others are healthy. When a technician talks about a generator fault, they mean a fault in this module, not in the pan or the glass. Repair or replacement of a generator is a job for a technician, and our guide on whether to repair or replace a La Cornue induction cooktop explains how to weigh it. Looking after the glass also matters; see cleaning a La Cornue induction glass surface.
