Electric Shower Wiring Tips

An electric shower can be a wonderful addition to your bathroom. It uses far less water than a bath, and you only heat the water you use, making it extremely economical. It’s even cheaper if you install it yourself. It’s not an especially complex job, but knowing the right way to do it will make things go much more smoothly.


Before you start any of the electrical work, ensure that the area around the bathtub is properly sealed. A shower will spray water around the tub area. If it’s not properly sealed, water could damage the structure of the house as it seeps through. It doesn’t take much time, and you’ll be grateful you did it.

Residual Current Device

It’s advisable to either have the electric shower on its own circuit or to fit a Residual Current Device (RCC), which will break the circuit and turn the device off in case of an overload. They aren’t easy to fit and should ideally be installed by a qualified electrician.


Be aware of what thickness of cable you should use for the electric shower. It’s dependent upon 2 factors, which are the kilowatt rating of the shower and the distance the cable must travel. As a rule of thumb, 10-millimeter squared cable will work. The cable should be routed separately from other cables. Avoid passing through insulation or thermal drywall.

Isolator Switch

An electric shower needs to have a double pole isolator switch that can’t be operated while the shower is running. If this is in the bathroom, it should be a pull cord switch with a light to show "on" or "off." Outside the bathroom, a regular switch with the "on/off" light is fine. The switch should have a rating of 45-amps for the electric shower.


Feed the cable into the switch. The ground wire will be screwed to the ground in the switch. The live and neutral wires go to the connector. The stripped ends are tightened in place. The wires from the electric shower to the switch feed to the other side of the connector block.

Connecting the Shower Wires

The wires from the electric shower need to be connected with the red wire stripped at the end and connected to the “L” terminal, the black wire to the “N” terminal, and the bare to the ground. Put sleeving over any bare wire to protect it from moisture and to avoid contact with other wires.