How La Cornue cookers report faults
La Cornue builds two broad kinds of cooking appliances, and they signal trouble in two very different ways. The electronic models — induction cooktops and range tops, electric and multifunction vaulted ovens, and the digital range hoods — carry sensors and a control board that can display an actual fault code. The gas and mechanical models — brass “flammes” gas burners, the cast-iron French top (plaque coup de feu), lava-rock grills, and gas vaulted ovens — have no electronics to throw a code, so they communicate through diagnostic symptoms instead.
Knowing which category your appliance falls into tells you what to look for. A cooktop or range top with induction zones can show E2, U400, a flashing U, or an Er message. A gas stove or vaulted oven instead tells you something is wrong with a yellow flame, a burner that will not stay lit, or an oven that drifts off temperature.
Electronic fault codes you may see
- E2 — the induction electronics are too hot, or a pan has boiled dry. Let the zone cool and check that the cooktop ventilation underneath is not blocked.
- U400 — the cooker is incorrectly connected at the supply (a wiring or voltage fault). The unit shuts off after about a second but the code stays on screen. This is an installation-level fault, not a cooking error.
- Er followed by a number — an internal technical fault on an induction module or multifunction oven that needs a technician.
- U flashing on a single zone — no pan, or incompatible (non-ferrous) cookware, is detected. If the right pan is in place and other zones still work, the coil or its sensor has likely failed.
- H — this is the residual-heat indicator, not a fault. The zone is still hot to the touch.
La Cornue induction zones also include an overheat function and a pan detector that will shut a zone off automatically. Those are protective behaviours, not failures. For persistent codes, our technicians read the control board directly during a service visit.
Gas and mechanical warning signs
Because gas burners, the French top, and gas vaulted ovens have no code display, you diagnose them by behaviour. The most common signs we see across La Cornue cooking appliances:
- Yellow or orange flame instead of blue — an air-to-gas mixture problem, often after an LP/NG conversion or a misadjusted air shutter.
- A burner that will not stay lit — usually a tired thermocouple or a safety valve that is not holding open.
- Clicking igniter with no flame — a wet, dirty, or cracked spark electrode.
- Oven temperature drifting hot or cold — the thermostat needs calibration or replacement.
- Weak or uneven burner flame — clogged burner ports or a blocked orifice.
- A gas smell — stop, ventilate, and treat this as urgent before any appliance work.
- The glow-bar igniter glows but the oven does not heat — a weak igniter that no longer draws enough current to open the gas safety valve.
What you can check first
- Note exactly what you see — the precise code, or the precise symptom (flame colour, smell, which zone, which burner).
- Try a power reset on electronic units — disconnect the cooker for 60 seconds, then restore power. Many one-off sensor reads clear this way.
- Check the simple causes — correct ferrous cookware on induction, clean and dry burner electrodes, unobstructed ventilation, fully seated burner caps.
- Do not ignore a U400 — a connection fault should be corrected before the cooker is used again.
When to call a La Cornue specialist
Some signs — a clean reset, a dried electrode, the right pan on an induction zone — you can resolve yourself. But a persistent Er code, a hi-limit safety thermostat that keeps tripping (part reference 06ELTS01), a gas valve that will not hold, a cracked or warped French top, or any gas odour calls for a trained technician. La Cornue appliances are hand-built to order by the Compagnons in France, with brass, vitreous enamel, and cast-iron components that demand the correct parts and a careful hand.
Our technicians diagnose and repair every La Cornue cooking appliance — Château and Grand Palais vaulted ovens, CornuFé range cookers, induction and gas range tops, French tops, grills, and range hoods. Work is backed by the manufacturer 5-year parts & labour warranty where applicable. You can verify model details and specifications on the official La Cornue website. When you are ready, schedule your repair — repair pricing starts from $X depending on the part and the appliance.