The lighting in a La Cornue range hood runs on small spotlight-style bulbs set into the underside of the hood, and they are simple enough that most owners can replace one themselves. What is easy to get wrong is treating a single dead bulb as something that can wait, or reaching for whatever bulb happens to be on hand instead of a proper match.
Why One Dead Bulb Should Not Wait
La Cornue’s own guidance is direct on this point: as soon as one bulb in the hood stops working, it should be replaced as quickly as possible, because the remaining bulbs can be put under extra load and fail sooner as a result. A single dark bulb is not just a cosmetic issue in the meantime — leaving it out invites a second bulb to fail not long after.
Replacing a Bulb Correctly
With the hood switched off and the bulb cool, remove the small glass frame covering it with a small screwdriver, then remove the bulb itself. The replacement should be identical to the original — same bulb type and the same power rating — rather than a higher-wattage substitute, since mismatched bulbs are part of what puts uneven load on the fixture. Handle the new bulb with a clean, dry, grease-free cloth rather than bare fingers; oils from skin can shorten a bulb’s life once it heats up. Reposition the glass frame firmly once the new bulb is seated.
When It Is Not the Bulb
If a replacement bulb of the correct type and rating still does not light, or if multiple bulbs go dark around the same time rather than one at a time, the problem has likely moved from the bulb itself to the wiring or switch behind the light circuit. That is electrical work inside the hood’s housing and is technician-only, unlike a straightforward bulb swap.
Cleaning the Fixture While You Are In There
Once a bulb is out, it is a convenient time to wipe the glass frame and surrounding hood ceiling, which can be cleaned with methylated spirits or white spirit once everything has cooled, the same product recommended for degreasing the hood ceiling generally. A clean fixture also makes it easier to see whether a socket looks discolored or damaged, which is worth mentioning if you do end up booking a repair.
Keeping a Spare on Hand
Because hood bulbs tend to be a specific type and rating rather than a common household size, keeping one correct spare in a kitchen drawer means a dead bulb can be replaced the moment it is noticed rather than left in place for days while a matching one is tracked down — which, given how quickly a single dead bulb can shorten the life of the others, is worth the small effort of having one ready.
If hood lighting on your range keeps failing even after a correct bulb replacement, a La Cornue range hood repair visit checks the light circuit itself rather than assuming another bulb will fix it.