Blog>Questions>Should my electric shower cable be 6mm or 10mm?
Last updated: 6 November 2023
Should my electric shower cable be 6mm or 10mm?
If you’re installing an electric shower in your bathroom, you might be unsure of what size shower cable you should use. Should your shower cable be 6mm or 10mm? Or something else entirely?
If you’re installing an electric shower in your bathroom, you might be unsure of what size shower cable you should use. Should your shower cable be 6mm or 10mm? Or something else entirely?
Here, we’ll help to demystify things for you. But first, bear in mind that you’ll need a competent installer to check the circuit and choose the correct cable size for you, in order to comply with Part P building regs. This is also super important for your safety – you don’t want to take any chances where there are electrics and water involved!
Factors affecting the cable size needed for an electric shower
The size of the cable needed for your electric shower isn’t straightforward. Rather, it will depend on a number of factors, including:
The kW rating of your shower
What method you use for cable installation
The length of the circuit
Any derating (where you reduce the ampacity of a cable)
For this reason, you should always check and follow the manufacturer’s installation guide. You’ll also need a competent installer to ensure the installation complies with Part P building regs.
Wondering how much it might cost for a professional to install an electric shower? Check out our guide to shower installation costs.
Should my shower cable be 6mm or 10mm?
As a general rule of thumb, a 6mm cable is usually adequate for showers that range from 6kW to 7kW. Meanwhile, a 10mm cable will often be recommended for showers that range from 7.5kW to 10kW. And if your shower has an even higher kW rating, a 16mm cable is likely going to be the best size.
Just bear in mind that this is only a rough guide and recommendations can vary based on lots of different factors, including those we mentioned earlier. So, always check the manufacturer’s installation instructions and get a Part-P certified tradesperson to confirm which size cable you need.
Find a qualified installer
Ready to get your electric shower installed? You’ll need to find a Part-P certified tradesperson to install your shower correctly and safely – including with the right cable size!
To find an experienced local shower installer, simply enter your postcode below and search our online directory.
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See the tradespeople we've checked and recommend for your job