La Cornue Château 90 Cooktop Repair in San Francisco

A cooktop, not a range

The Château 90 cooktop is a rangetop in the Château G4 series, 35 1/2 inches across. It carries no oven, so everything we examine sits at counter level: burners, igniters, valves, knobs and the way the unit is seated in the countertop. It is a current model, listed among La Cornue rangetops and handled under La Cornue rangetop repair.

Owners often pair it with a separate wall oven, so a complaint that begins with a burner stays about the burner. The oven is its own conversation.

Typical problems on a counter-level unit

• A burner fails to catch even though its neighbors light at once.
• Sparking continues after a flame appears, or starts on its own near a spill.
• A knob turns with a gritty feel or sits looser on its stem.
• The flame looks ragged on one side because a head is not fully seated.
• Gas can be smelled around the cooktop. If so, leave and call the gas utility or 911 from outside.

Spills are the chief enemy of a cooktop. Liquid that runs under a cap can wet the igniter and make it spark without lighting, and sugary boil-overs bake onto burner ports. A dry cap and a cleaned port solve more cases than owners expect.

The cutout, the supply and the space below

A cooktop depends on its cutout. The unit sits in a hole in stone or wood, with a gas line coming up through the cabinet beneath and an electrical connection for the igniters. When the cabinet below is used for pots, a gas connector can get bumped, and drawers placed under the unit can crowd the supply. In older San Francisco houses with retrofitted gas lines, the shut-off sometimes sits somewhere awkward behind the drawers. Know where yours is.

The hood above matters too. A cooktop of this width pushes a lot of heat and moisture upward, and a hood that has stopped pulling air can leave grease on the caps and knobs. See hood noisy or weak if that fits.

Owner checks that stay on the surface

Switch the unit off and let it cool. Lift each cap and head, wipe them, let them dry, and replace them so they sit flat. Confirm the gas valve under the counter is open, and look at the breaker. Then try each burner and report which ones respond. Do not remove the cooktop, do not loosen fittings, and do not bypass any switch.

Telling the 90 from its neighbors

The Château 75 cooktop is the narrower sibling, and the Château 90 range shares the width but includes an oven. The model and serial plate, usually found under the front edge of the cooktop or inside the cabinet below, identifies yours. Our note on finding the model number covers the details.

Frequently asked questions