How to fit a bathroom shaver socket

Helpful video reference. John Ward of Flameport Electrical in Poole — one of the most respected UK electrical educators online — explains shaver sockets in his video "Shaver Sockets for UK Bathrooms — With Isolating Transformer". He covers the isolation transformer inside the unit, why it matters, and the outlet types. Worth watching before you start, especially if you have never worked on a bathroom circuit before.

1. Why a bathroom needs a special socket

Standard 13A sockets are banned in bathrooms. The risk of moisture, wet hands and exposed metalwork nearby makes a direct mains socket too dangerous. BS 7671 Section 701 allows only shaver sockets complying with BS EN 61558-2-5, which contain a safety isolating transformer.

The transformer inside a shaver socket does two things. It steps down and isolates — so the secondary (output) circuit has no direct connection to the mains earth. This limits the fault current through a person in contact with the secondary side, making the socket far safer near water than any standard 13A outlet.

The sockets typically offer both 115V and 230V outputs. The 115V is for older US-style shavers. Modern shavers work on either, so in practice most people just plug in and it works.

2. Check the location

The bathroom zone rules under BS 7671 Section 701 define where equipment can be installed. Zone 0 is inside the bath or shower. Zone 1 extends 2.25 m above the floor directly above the bath or shower and 0.6 m horizontally from the edge. Shaver sockets must not be in Zone 0 or Zone 1.

In practice, "above the basin on the wall between the door and the mirror" is where most shaver sockets end up, and that position is normally well clear of both zones. If your bathroom is very small or the basin is directly adjacent to the bath, measure carefully before deciding where to fix.

3. Choose your wiring source

Three options exist. The most common is a spur from the ring main — run 2.5 mm² twin-and-earth from a nearby socket, via a fused spur (3A fuse) or directly if local conditions allow. The second option is to feed from the bathroom lighting circuit via a 3A fused connection unit (FCU), using 1.5 mm² twin-and-earth from the FCU output to the shaver socket. The third is a dedicated circuit from the consumer unit, which is overkill for a shaver socket but is sometimes done during a full bathroom refurbishment.

Running new cable into a bathroom is Part P notifiable work. For a like-for-like replacement using the existing cable, you are working on the connection only.

4. Isolate the circuit

Switch off the circuit at the consumer unit. If feeding from the lighting circuit, switch off the bathroom lighting circuit. If feeding from the ring main, switch off that circuit. Test for dead at the supply point — not just at the socket position — before cutting or connecting anything.

5. Prepare the back box

Shaver sockets are often surface-mounted in bathrooms because chasing a back box into tiled walls is not always practical. Fix the surface box to the wall at a comfortable height — typically 900 to 1200 mm from the floor. Drill and plug or use suitable fixings for the wall type. Thread the cable into the box through the knockout or gland.

6. Connect the wiring

The connections on a shaver socket are the same as a normal socket: L (line) for brown, N (neutral) for blue, E (earth) for green-yellow. Some older shaver sockets had just two terminals with no earth — if the replacement unit has an earth terminal, connect the earth conductor. Tighten each terminal firmly and check that no stray copper strands could touch adjacent terminals.

7. Refit and test

Fold the cable neatly into the box, fit the faceplate, and tighten the screws. Restore power. Test by plugging in a shaver or a phone charger in the 230V output. If the socket does not power anything and the circuit has not tripped, check your connections — particularly that L and N have not been transposed.

When to call us

Replacing an existing shaver socket is a straightforward job. Installing one where there was not one before — which means new cable in a special location — requires a registered electrician or a building control notification. Richard can fit shaver sockets as part of a bathroom refurbishment or as a standalone job.