Replace a cooker switch like-for-like

Replace a faulty cooker switch with an identical one, wiring it safely and testing power before finishing the job.

CS-01Check the old switch and buy an exact matchLook at the rating plate on the existing switch — most cooker switches are 45A double-pole, and some include a 13A switched socket. Buy a replacement with the same rating and function, and check the faceplate size (usually 86x86mm single, or 146x86mm double) matches your existing backbox so you don't need to patch the wall.

1 each · 45A double-pole cooker control switch (like-for-like)

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CS-02Isolate the cooker circuit and prove it's deadTurn off the cooker circuit breaker at the consumer unit — usually a 32A or 40A double-pole breaker or RCBO — and lock it off or tape over it so no one switches it back on while you're working. Use your voltage tester across live-neutral, live-earth and neutral-earth on both sides of the switch to prove it's dead before you touch any conductor. Cables can run almost anywhere behind a kitchen wall, so treat everything as live until you've proven otherwise.

RULES

1 each · Voltage tester (two-pole)

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1 each · Circuit lock-off or tape

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KNOW THE RULES

In England, Part P of the Building Regulations covers electrical work in kitchens. A straightforward like-for-like swap of an existing switch is not notifiable work, but it must still meet the safety standard in BS 7671. If you're not confident, get a registered electrician (Part P scheme) to check it or do it for you.

CS-03Remove the old switch faceplateUndo the two fixing screws holding the faceplate to the backbox and ease it forward. Take a photo of the wiring before you disturb anything. There are usually two cables in a cooker switch — a feed from the consumer unit and an outgoing cable to the cooker outlet plate or terminal block. Loosen the terminal screws and lift the old switch clear.

CS-04Check the backbox and identify the wall behind itIf the existing backbox is sound and staying where it is, skip to wiring the new switch. If you do need to remount or reposition it, work out what's behind the wall first: track a line of screw heads with a stud detector or magnet, and listen for a hollow sound between fixing points. Drill a small pilot hole — fine timber dust means a timber stud, grey metallic swarf means a metal stud, and a hard, solid feel with no hollow sound means solid brick or block.

CS-05Fix or refix the backbox for your wall typeCables and pipes can run almost anywhere, and a detector won't catch everything — deep cables, ones in metal conduit, behind metal-backed board, or outside the normal safe zones can still be missed, and a metal stud frame confuses cheap detectors further. Before you drill, find your stopcock (usually under the kitchen sink) and check it turns. If there's any doubt, isolate the circuit at the consumer unit and turn off the water at the stopcock before you drill or cut. Then fix according to what you found: solid brick or block — drill a 6mm hole 35mm deep and use a wall plug with a 30mm screw; plasterboard on timber studs — drive a screw straight into the centre of the stud; plasterboard on metal studs — use a self-drilling metal-stud fixing or a toggle-type hollow-wall anchor, never a wood screw or plain plastic plug, which strips straight through 0.5mm steel; dot-and-dab — use a fixing 50-65mm long so it passes through the board and adhesive dabs and bites into the masonry behind; lath and plaster — screw into a lath or a noggin, not into the bare plaster, which will crack. A metal-stud fixing will hold a light switch faceplate fine, but it won't hold anything heavier that pulls on it — if that's your situation, fit a timber noggin between the studs or fix through to the masonry behind instead.

1 pack · Wall plugs (assorted, 10-pack)

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4 each · Masonry screws, 30mm

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1 pack · Metal-stud toggle fixing (2-pack)

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CS-06Wire the new switchMatch the new switch's terminals to the wiring layout you photographed. Connect the incoming feed to the 'in' terminals and the outgoing cable to the 'out' terminals — live, neutral, and earth. Sleeve the earth conductor in green/yellow sleeving if it isn't already, and connect it first. Give every terminal a firm tug test — no bare copper should be visible outside any terminal.

1 metre · Green/yellow earth sleeving

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CS-07Mount the switch and close it upFold the cables neatly back into the backbox so nothing is trapped or strained. Offer the switch up and screw the two fixing screws in evenly so the plate sits flush and square. Don't overtighten — it's easy to crack the faceplate.

CS-08Restore power and testTurn the cooker circuit breaker back on at the consumer unit and switch the new cooker switch on. Check the neon indicator lights if one is fitted, then turn the cooker on briefly to confirm it powers up. After ten minutes, check the switch and cable entries for warmth or a burning smell. If an RCD trips, turn everything off and check your connections before trying again.

CS-09Tidy up and dispose of the old switchSweep up any dust or offcuts and wipe the wall down. Put your tools away. Take the old switch to a household recycling point rather than the bin — it contains metal and small electrical components.

KNOW THE RULES

Before you start: Which electrical jobs can I do myself? Part P explained

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