--- title: "La Cornue CornuFé induction range showing U400" description: "What U400 means on La Cornue CornuFé induction ranges, what to check before booking, and when it is not a failure at all." url: "https://rangerepair.center/error-codes/la-cornue-u400/" --- # La Cornue CornuFé induction range showing U400 U400 is the CornuFé's way of saying its electrical connection is not correct. ## What U400 actually means. U400 is the CornuFé's way of saying its electrical connection is not correct. Within about a second of power-up the control shuts off, and the code remains on the display until the connection is fixed. La Cornue range display What to do when U400 shows on the range ### Kind of code Controls and communication The display, the main board or the induction power board lost contact with one another, or one of them failed its own self-check. A power dip, a loose cable or moisture from a boil-over is ruled out before a board is replaced, and a range that keeps heating while this code shows is switched off at the breaker. ### Usually leads to Knobs, switches and controls Knobs that spin or crack, touch keys that do nothing, blank displays, clocks that reset and control boards that switch the wrong thing. ### Shows up as Range Error Code The range display shows letters, numbers or a flashing symbol, beeps, and stops the oven, a cooking zone or a clean. ### Make La Cornue A French maker of hand-assembled ranges, known for vaulted oven ceilings and custom finishes. ### Source CornuFé 110 Induction Installation & User Guide CornuFé 90 and 110 induction ranges; the code concerns how the range was connected to the supply. ## Before you book, in this order. Each step comes from La Cornue's own guidance for U400 on its ranges. Follow it to the end: the last card says whether this is a visit. 01 Turn the range off at its breaker. 02 Book a visit to have the supply connection inspected before the range is used again. ### Still there? It usually turns into [knobs, switches and controls](https://rangerepair.center/services/knobs-switches-and-controls/). Book with the code and the model number. ### What not to do No pan, setting or cleaning habit causes U400, and switching it off and on will not make it go away. ## What you may notice with it. The range problems U400 tends to arrive with. Answer these at the range before anyone is booked. [All problems](https://rangerepair.center/problems/) Before you call ### [Range Error Code](https://rangerepair.center/problems/range-error-code/) [All 6 causes, cheapest first](https://rangerepair.center/problems/range-error-code/) It also comes with - [**Range Control Panel Not Responding**](https://rangerepair.center/problems/control-panel-not-responding/) Problem ### Range Error Code 6 causes, cheapest first Where U400 usually leads ## Knobs, switches and controls. **Knobs, keypad or control board · moderate.** Book a visit [What the job involves](https://rangerepair.center/services/knobs-switches-and-controls/) ## La Cornue ranges. A French maker of hand-assembled ranges, known for vaulted oven ceilings and custom finishes. [La Cornue range repair](https://rangerepair.center/brands/la-cornue/) More La Cornue codes [E2](https://rangerepair.center/error-codes/la-cornue-e2/) [Er](https://rangerepair.center/error-codes/la-cornue-er/) [U](https://rangerepair.center/error-codes/la-cornue-u/) [E](https://rangerepair.center/error-codes/la-cornue-e/) [H](https://rangerepair.center/error-codes/la-cornue-h/) [L](https://rangerepair.center/error-codes/la-cornue-l/) Controls and communication on other makes [AGA FE](https://rangerepair.center/error-codes/aga-fe/) [BlueStar F20](https://rangerepair.center/error-codes/bluestar-range-f20/) [Bosch e005](https://rangerepair.center/error-codes/bosch-e005/) [Café F7](https://rangerepair.center/error-codes/cafe-f7/) [Dacor C-d0](https://rangerepair.center/error-codes/dacor-range-c-d0/) [Electrolux Err](https://rangerepair.center/error-codes/electrolux-err-number/) [Fisher & Paykel F + number](https://rangerepair.center/error-codes/fisher-and-paykel-range-f-number/) [Frigidaire F1](https://rangerepair.center/error-codes/frigidaire-f1/) [All 70 codes of this kind](https://rangerepair.center/error-codes/#family-communication) La Cornue builds this ### Gas range Open flames on top and a gas-fired oven below, all fed by one supply line behind the range and lit by igniters rather than a match. La Cornue builds this ### Dual-fuel range Gas burners on top and an electric oven below, the combination most professional-style ranges use, needing both a gas line and a 240-volt circuit. La Cornue builds this ### Induction range A glass top that heats the pan itself through copper coils and power boards, over an electric oven, with electronics doing almost all the work. ## In La Cornue's own words > The cooker has been incorrectly connected. The control will switch off after approximately 1 second and the error code will be permanently displayed. [CornuFé 110 Induction Installation & User Guide](https://d2a7uujil7d64c.cloudfront.net/file/450) Every code on this site is taken from the manufacturer's documentation, never from a forum or a parts listing. CornuFé 90 and 110 induction ranges; the code concerns how the range was connected to the supply. ## La Cornue U400 range repair, where we come out. The same visit in every metro below: the code, the model number, and a diagnosis before any part is ordered. 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Turn the range off at its breaker. If it comes back, it needs a visit. ### Why did U400 show the first time my La Cornue CornuFé was turned on? The code points to how the range was connected to the house supply. It needs correcting at the connection before the range is used. ### Can I cook on my CornuFé oven while U400 is on the display? U400 concerns the range's supply connection, so leave the whole range off at the breaker until the connection has been checked. --- **[Read on the site: La Cornue CornuFé induction range showing U400](https://rangerepair.center/error-codes/la-cornue-u400/)** **[Book a visit with RangeRepair.center](https://rangerepair.center/schedule/)**