La Cornue Induction Error Codes: E, E2, Er, U and U400

Induction cooktops tell you what is wrong through the display, and La Cornue induction modules and ranges are no exception. For this site, five messages are documented in the library: E, E2, Er followed by a number, U, and U400. Each has its own page under error codes. This article puts them side by side, so you can see which one you are looking at and what the sensible next move is. We do not cover any other code or reset sequence, because only these five are verified.

At a glance

U: no pan or the wrong pan

This is the friendliest message. It appears when the cooktop cannot detect a pan on the zone, or when the pan is not suitable for induction, and it clears when a suitable pan is placed on the zone. Check that the pan is made of a material that works with induction, that it sits flat and centred on the marked zone, and that it is not much smaller than the zone. If a pan that previously worked now triggers the message in every zone, that is a different matter. See La Cornue induction pan not detected for the logic, and the code page La Cornue cooktop U error.

E2: electronic unit too hot

E2 means the electronics have become too hot, and it can also show if a pan boiled dry. Switch off, let the cooktop cool, and make sure nothing blocks air movement around the unit. Check the pan you were using and avoid heating an empty or nearly empty pan. If the message returns under normal cooking, a cooling fan, a sensor or a component may be at fault. The details are on La Cornue cooktop E2 error, and the shut-off behaviour is in La Cornue induction cooktop shuts off.

E: electronic failure

E is described as an electronic failure on the display. It is not a pan problem and is not something owners clear by changing cookware. Note the exact wording, switch off at the breaker once for a controlled power reset, wait, and restore. If it comes back, stop using the cooktop and book a visit. The page for it is La Cornue cooktop E error.

Er plus a number: internal technical fault

The number following Er identifies a particular internal fault, and the documentation states that the user cannot rectify it. Write down the full text exactly, including the number. That detail helps a technician arrive with the right expectations. See La Cornue cooktop Er error.

U400: incorrectly connected

U400 means the cooker is incorrectly connected. The control switches off after about a second and the code stays on the display. This usually shows up after a new installation, a relocation or work on the electrical supply, which is why it matters who connected the range. It is a connection issue, so it is not something to solve by trying more pans or resetting repeatedly. The page is La Cornue cooktop U400 error.

A calm order of operations

1. Read the message and write it down exactly, including any number.
2. If it is U, test a suitable, flat pan, centred on the zone.
3. If it is E2, switch off, allow the unit to cool, and avoid heating an empty pan.
4. For E, Er or U400, do not keep trying; perform at most one controlled power reset and note the result.
5. Make sure the breaker is on and the surface is clean and dry.

Do not open panels, test live circuits or bypass switches. Burning smells or sparks mean power off at the breaker.

When to book

Book when any message other than U repeats, when U appears with every pan, or when the cooktop shuts down mid-cooking. A visit starts with diagnosis, comes with a written estimate, and nothing is repaired without your approval. See La Cornue induction cooktop repair, and for the lineup, La Cornue induction cooktops. Induction modules appear on both Château and CornuFé ranges, so include the model and serial plate details and the exact text on the display.

Which version of the cooktop do the codes belong to

The library ties these messages to particular lines. E and U are recorded for the Château induction module, which belongs to the G4 series covering Château 90, 120 and 150 and the induction ranges. E2, Er with a number and U400 are recorded for CornuFé induction ranges. If you have a different arrangement, or a message not in the table, write the text down and mention it when you book; we do not guess at codes outside the documented five.

Habits that keep messages away

Use flat, clean pans that suit induction and sit centred on the zone. Do not heat an empty pan. Wipe spills once the surface has cooled, keep the area around the cooktop clear, and avoid stacking items on the surface. If you recently had work done on the electrical supply, mention it, because that is the usual background to a connection message. In busy Bay Area households where several people cook, a short note stuck inside a cabinet door with these points helps everyone use the cooktop the same way.

Frequently asked questions