--- title: "Cooktops and rangetops" description: "La Cornue cooktops and rangetops — a La Cornue cooktop is a set of modules chosen at order time and dropped into a stainless frame: brass gas burners at…" url: "https://la-cornuemiami.support/appliances/cooktop/" date_modified: "2026-09-03" Appliance type: "Cooktops and rangetops" --- # La Cornue cooktops and rangetops ### The top is a set of choices, and every choice is a different repair La Cornue prices its cooktop elements individually, which tells you how the appliance is meant to be understood. Everything below belongs to the top of a range; the same modules sold as a unit that drops into a counter with no ovens under it are a rangetop, T40 to T48, and that is a separate page on this site. On the Château series: two brass gas burners in an enamelled drip tray, 17,000 BTU at the front and 7,500 at the back on natural gas. A 22,000 BTU power burner for a stock pot. The plaque coup de feu, large or petite, where one 7,500 BTU burner heats a solid cast-iron plate that becomes the whole cooking surface, hottest above the burner and cooler as you work outwards. A lava-rock grill at 14,500 BTU. Ceramic-glass induction, 2,100 watts a zone and 3,700 on boost. An electric teppanyaki plate running from 140 to 482 °F. On a single rangetop you might have four of those, and the diagnosis for one tells you nothing about the next. The factory-built CornuFé is specified differently and it is worth knowing which you have: a 17,500 BTU central burner, three at 12,000 and a 6,000 BTU simmer burner on the dual-fuel models, and five separately rated induction zones from 1.4 kW to 2.3 kW on the induction ones. ### Induction is the one place this make talks back The gas half of the line has no diagnostic system at all, so the induction and teppanyaki electronics are the only part of a La Cornue cooktop that reports anything. Three codes, all documented by the maker: **E2**, the electronic unit is too hot, check ventilation, or a pan has boiled dry; **U400**, the cooker has been incorrectly connected, control off after a second and the code latched on; **Er** with a number, an internal problem the user cannot clear. Everything else the display shows is an indicator rather than a problem — H for residual heat above 140 °F, the pan-missing symbol when a zone has nothing on it or the base is too small, L for child lock, A for automatic heat-up, P for boost. Knowing which is which saves a call: an H is the cooktop telling you it is still hot, not that it is broken. ### Cracked glass, and why we disconnect it before we discuss it A crack in a ceramic-glass induction hob is the one problem on this appliance with a safety instruction attached, and La Cornue’s guide is unambiguous: disconnect the cooker from the power supply immediately and do not use it until it has been repaired. The reason is that the glass is what separates the coils and the electronics from whatever gets spilled on the surface. We will come and look at a cracked hob, and the first thing we do is make it safe rather than test it. Minimum pan diameters are worth knowing too, because they are the honest answer to a zone that seems weak: 4¾ inches front left, 5½ at the rear, 8¼ in the center. A pan smaller than the zone will not couple properly, and the cooktop is behaving exactly as designed. Brass gas burners · plaque coup de feu · lava-rock grill · induction · teppanyaki Cooktop repair Gas, induction, French top, grill and teppanyaki modules on one frame Induction is the only half of this line that shows a code — E2, U400, Er A cracked glass hob is disconnected first and diagnosed second The top is a set of choices, and every choice is a different repair La Cornue prices its cooktop elements individually, which tells you how the appliance is meant to be understood. Everything below belongs to the top of a range; the same modules sold as a unit that drops into a counter with no ovens under it are a rangetop, T40 to T48, and that is a separate page on this site. On the Château series: two brass gas burners in an enamelled drip tray, 17,000 BTU at the front and 7,500 at the back on natural gas. A 22,000 BTU power burner for a stock pot. The plaque coup de feu, large or petite, where one 7,500 BTU burner heats a solid cast-iron plate that becomes the whole cooking surface, hottest above the burner and cooler as you work outwards. A lava-rock grill at 14,500 BTU. Ceramic-glass induction, 2,100 watts a zone and 3,700 on boost. An electric teppanyaki plate running from 140 to 482 °F. On a single rangetop you might have four of those, and the diagnosis for one tells you nothing about the next. The factory-built CornuFé is specified differently and it is worth knowing which you have: a 17,500 BTU central burner, three at 12,000 and a 6,000 BTU simmer burner on the dual-fuel models, and five separately rated induction zones from 1.4 kW to 2.3 kW on the induction ones. Induction is the one place this make talks back The gas half of the line has no diagnostic system at all, so the induction and teppanyaki electronics are the only part of a La Cornue cooktop that reports anything. Three codes, all documented by the maker: E2, the electronic unit is too hot, check ventilation, or a pan has boiled dry; U400, the cooker has been incorrectly connected, control off after a second and the code latched on; Er with a number, an internal problem the user cannot clear. Everything else the display shows is an indicator rather than a problem — H for residual heat above 140 °F, the pan-missing symbol when a zone has nothing on it or the base is too small, L for child lock, A for automatic heat-up, P for boost. Knowing which is which saves a call: an H is the cooktop telling you it is still hot, not that it is broken. Cracked glass, and why we disconnect it before we discuss it A crack in a ceramic-glass induction hob is the one problem on this appliance with a safety instruction attached, and La Cornue’s guide is unambiguous: disconnect the cooker from the power supply immediately and do not use it until it has been repaired. The reason is that the glass is what separates the coils and the electronics from whatever gets spilled on the surface. We will come and look at a cracked hob, and the first thing we do is make it safe rather than test it. Minimum pan diameters are worth knowing too, because they are the honest answer to a zone that seems weak: 4¾ inches front left, 5½ at the rear, 8¼ in the center. A pan smaller than the zone will not couple properly, and the cooktop is behaving exactly as designed. ### The induction zone shows E2 and shuts off. What is that? That is one of exactly three codes La Cornue prints anywhere in its US documentation, and it means the electronics under the hob are too hot. The manual's own first suggestion is ventilation — how the cooktop is installed and whether air can get to the electronics — and its second is a pan boiled dry, which heats the glass and everything under it. So before we condemn a board we look at the installation: what is packed into the cabinet underneath, whether a fitted drawer or a filled cavity has closed off the air path, whether it happens only during long cooking or from cold. If the ventilation is right and it still cuts out, the problem is in the unit and it is a part. What we will not do is reset it, hand it back and let it cook itself. ### U400 came up and the top will not run at all. U400 means the cooker has been incorrectly connected, in La Cornue's own words. The control shuts down after about a second and the code stays on the display permanently until the wiring is right. It is an electrical-supply problem rather than an appliance failure, and it turns up most often after something changed: a new installation, a panel or breaker replaced, a range moved, work done on the kitchen circuit. That makes it one of the few problems on this make where the answer might be that nothing inside your range is broken. We check the supply and the connection at the appliance against the specification, and if the problem is upstream we say so in writing rather than sell you a board. ### My French top has a crack across it. Is it finished? Not necessarily, but it needs looking at rather than living with. The plaque is a single cast-iron plate heated by one 7,500 BTU burner directly beneath its center, and it is meant to run through a large temperature range and hold heat — so it is under stress every time it is used. Hairline crazing in the seasoning is cosmetic. A crack through the iron changes how heat crosses the plate, and a plate that has been thermally shocked (a wet cloth, a pan of cold liquid on a hot center) can go further. We will tell you which one you have. The other thing we look at is what is under it: a burner running rich, or a blocked drip area, puts more heat into one spot than the plate was designed to spread. ### Only one gas burner will not light, and it clicks. Clicking with no ignition on one burner is nearly always the electrode or the burner ports rather than the ignition module, because a failed module takes all the burners with it. In this climate the usual causes are moisture and cooking residue: a wet electrode after a cleaning, a cracked ceramic that is arcing to the wrong place, or ports partly blocked so the flame cannot travel to the spark. It is a small job and a same-visit one in most cases. Please do not keep holding the knob in while it clicks — that is unlit gas going into your kitchen, and the burner is not worth it. --- **[Read full article: Cooktops and rangetops](https://la-cornuemiami.support/appliances/cooktop/)**