Electric shower installation guide
By Jess O'Leary
Discover everything you need to know about installing an electric shower in your bathroom from the experts at Which?
Because electric showers combine water and electricity, it’s vital that they are installed correctly and safely.
If you’re installing a new electric shower from scratch, you'll need to get it installed by a Part P-certified plumber or electrician, who'll be able to install, upgrade or check the wiring to ensure that the shower works safely.
If you’re replacing an existing electric shower unit like-for-like, you may be able to install it yourself. In this case, the power and water cabling is already in place, and installing a new one simply involves fitting a new shower unit and riser rail. However, if the new shower unit has a higher wattage than the old one an electrician should replace the unit as the cabling may need changing. If in doubt, always err on the side of calling in a professional.
Don't miss our best electric shower recommendations, as revealed by Which? lab tests.
Are some electric showers easier to install than others?
The easiest showers to install are models that have top, bottom, side and rear cable and pipe entry points, to make routing them easier.
As the cables are often large and inflexible, showers with more space inside the casing and well-designed connection blocks will make life easier for the installer. Likewise, look for swivelling water connections with plenty of room for a spanner.
To complete the job, ensure that the riser rail and shower handset will be high enough for the tallest person likely to use the shower, and also low enough for children.
How much does professional electric shower installation cost?
Having an electric shower professionally installed makes up a big part of the overall cost of getting a new shower. Even a simple installation, where the cold water supply is easily accessible and the route from the shower to the shower unit (main electrical supply) is simple, can cost more than the shower itself.
Prices vary depending on the tradesperson or company you use, so it’s worth getting a few quotes before you go ahead.
What are the plumbing requirements when installing an electric shower?
The plumbing involved is fairly simple. All that’s needed is plumbing to a mains cold water supply with 15mm diameter pipe.
What are the electrical requirements when installing an electric shower?
Installing the electrical supply is a little more complicated than getting the plumbing set up.
The size of cable and fuses for electric showers can vary, depending on the power (in kW) of the shower. We’d recommend choosing a 10sq mm cable, as this means you’ll be able to replace your shower in the future without having to install a larger cable.
The electrics will need to be connected to a separate fused electrical supply circuit. And for safety, you'll need a ceiling-mounted double pole switch (with neon and mechanical indicators) to turn the electricity supply to the shower on and off.
How can I find an electric shower installer I can rely on?
The easiest option is to choose an installer who is a member of a self-certification scheme such as those listed below. You can get more details of these competent-person schemes from your local council’s Building Control.
- BRE Certification
- British Standards Institution
- NAPIT Certification
- NICEIC Certification Services
You can also use Which? Trusted Traders to find an endorsed plumber or electrician in in your area.
Before the installer begins work, agree with them that they will take responsibility for ensuring the installation complies with the building regulations and will provide the BS7671 certificate. You will need to produce this if you want to sell your home to prove that electrical work has been carried out safely.