How To Install Bathroom fittings

The bathroom can be one of the most dangerous places in the home if you don’t follow the rules for electrical safety. But it can also be one of the most comfortable with the introduction of electrical fittings. As long as you install them correctly they will not only work at maximum efficiency, but need never be a cause for anxiety to you or your family.

There is nothing worse than a bleak, chilly bathroom to greet you on a cold morning. Yet even the largest bathroom can be greatly improved with the addition of a wall-mounted infra-red heater for instant warmth, a small oil-fitted electric radiator. A heated towel rail (to warm towels when you have a bath and to dry them afterwards), a combined heater/light unit or a shaver socket combined with a mirror light.

Two important factors, however, must be remembered: these installations must be correctly wired and appliances must be fixed so securely that they can be removed only by using proper tools. Correct wiring means no socket outlets — except for the shaver — are permitted inside a bathroom (or washroom) and only cord-operated switches are allowed inside. And the usual general warning must be repeated: always switch off at the mains before you begin any electrical work.

Heated towel rail

A good selection of these is available, so choose the largest one that will fit in your bathroom. It is a good idea to buy one that incorporates a pilot light because this means you are less likely to forget to turn it off. Towel rails must be connected to the ring circuit through a switched fused connection unit that is sited outside the bathroom.

Decide where you are going to install the appliance, first making sure the plaster or plasterboard wall is strong enough to make a secure fixing. Use a spirit level to check the appliance is being fixed horizontally and mark with a pencil the fixing holes for the screws. Drill and plug the holes.

Prepare the route for your cable (2.5sq mm twin core and earth PVC-sheathed) from the ring circuit to the switched fuse connection unit; install the unit as close to the appliance as possible — but outside the bathroom. Decide on the route for the appliance flex to reach the connection unit. If this entails a long run you may have to install a flexible cord outlet box — linked to the connection unit with 1.5 sq nun twin core and earth cable. The wires from the appliance are then connected to their corresponding terminals on the cord outlet box.

When you have completed the installation, check all terminal and fixing screws, turn on the mains and switch on the appliance to check it is working. Oil-filled radiator The installation method for oil-filled radiators is similar to that for fitting a heated towel rail.

Wall heater

This must also be fed from the ring circuit, using a switched fused connection unit and a flexible cord outlet as described for a towel rail. The heater should be fixed as high on the wall as possible and preferably not above a bath or a shower. Alternatively you may connect the appliance to a cord-operated isolating switch (incorporating a pilot light) and connect the switch to the ring circuit via a connection unit as before.

The appliance is fixed to the wall with plugs and screws; always ensure it is properly secured before connecting up and switching on.

Light/heater units

The ultimate in space-saving, this unit incorporates a lamp in the centre of a ceiling fitting with a heating element around the outside. A cord-operated switch within the unit operates the heater. The master switch should be a cord-operated ceiling switch. It should not be connected to a lighting circuit because many units have a total loading of 850 watts and if used simultaneously with a number of other lights on the circuit it could overload the maximum 1200 watts capacity and cause a fuse to blow in the consumer unit — not a happy thought if you are in the bath at the time.

There are two ways of supplying such a unit. One is through a switched fused connection unit, the other by running a separate circuit from a spare fuseway in the consumer unit, using either I or 1.5sq mm twin core and earth cable. You must take great care in connecting up at the consumer unit; the circuit should be controlled by a 5amp fuse.

The appliance should be securely mounted to a timber batten screwed between joists in the ceiling or roof space. Connect the ceiling cord-operated switch between the appliance and the connection unit; if you are running the appliance from the consumer unir, fit an isolating ceiling cord-operated switch within reach of the appliance.

Ceiling rose

If by installing a heat/light unit you are making the existing ceiling rose redundant, you must remove the pendant flex, rose, switch wires and switch. Having disconnected the switch wire at the rose, disconnect at the switch or switches; pull the cable through from the ceiling space and discard it, replastering any recess where the switch was fixed.

You must install a junction box between the joists above the rose and use this to seal off (or terminate) the cables that run to the rose. You will have to take great care doing this, ensuring the conductors fitted to the rose are connected to their corresponding terminals in the junction box. With an older installation, earthing was probably not used; if earthing is used, connect the earth to its proper terminal in the box. With an older installation you may have difficulty identifying all the cables. If you have any doubts, always seek expert advice — don’t trust your own judgement.

Shaver sockets

The specially designed shaver socket for use in the bathroom is available in several types: some come complete with a mirror light. The shaver supply unit can be connected directly to the lighting circuit without using a fuse in the spur, because it contains an isolating transformer. The unit has a two-pin socket that accepts British, Continental and American standard round and flat-pin plugs. It is possible to buy a dual voltage socket outlet for 240 or 115 volts in cases where the shaver does not adapt. Shaver sockets are also made without isolating transformers for use in other rooms.

It is impossible to run other appliances off a shaver socket because a thermal unit will cause them to cut out.

Remember when installing a shaver socket that anyone who is short-sighted needs to get quite close to a mirror with their spectacles off. So avoid placing it over a deep sink or cupboard that forces them to stand and peer. If you have a rechargeable electric razor, make sure there is a shelf near the socket where you can leave the shaver to recharge.

Mirror light

This is a boon when you are making-up, or shaving with an electric or wet razor. Units are available which combine a striplight and a shaver socket at the end.


Having decided the position of the shaver and/or mirror light unit, trace a pencil outline round the box (available flush, semi-flush or surface-mounted) or mark the securing screw holes. Thread your cable through a hole drilled in the wall through the back of your surface-mounted box or through knock-out holes. Secure the box. Trim the cable sheath, strip the insulation material and connect up in the normal way to the correct terminals. The earth terminal is generally riveted in the base of the box; the live and neutral conductors go to terminals on the reverse side of the socket unit. Then secure the unit to the box with the screws provided, turn on the mains and test the light.


If you have any doubts about the safety or suitability of a product, don’t buy it. The yellow and blue label of the British Electrotechnical Approvals Board attached to a product proves it has been tested to the British Standard for electrical safety.

As an alternative to making the existing wiring and ceiling switch redundant, you may decide to alter your lighting by converting them to operate a wall light suitable for use in a bathroom.

Replace the rose with a junction box, and reconnect the ceiling switch wires to the switched live, live and earth terminals in the junction box. Measure a length of lsq mm two core and earth cable (which is standard for lighting circuits) to run from the junction box across your roof or ceiling space and down the wall to the new light position. You should channel the cable into the wall and then replaster. Connect the cable to the switched live, neutral and earth terminals in the junction box and the corresponding terminals on your wall light, which will have been fixed to the wall.

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