An electric shower is one of the biggest single loads in a house, drawing more than most kitchens, which is why swapping one is only sometimes a simple swap. I install and replace electric showers across Bristol, sized to the circuit that actually feeds them, certified under my NICEIC registration.
Like-for-like replacement vs a new install: why the kW rating changes the job
Same kW rating, same position: a straightforward replacement, done in a couple of hours. Higher kW, and here's the physics the shower aisle doesn't mention: a 10.5kW shower pulls meaningfully more current than the 8.5kW it replaces, and the existing cable and protective device were sized for the old one. Upgrading the shower without checking the circuit is how cables cook quietly inside walls. So the first question in my reply is always the model you have and the model you want, because that pair decides whether you're buying two hours or a new circuit.
Why shower circuits fail EICRs
Shower circuits are the serial offenders on EICRs: undersized cable feeding an upgraded unit, no RCD protection on a circuit that runs through a wet room, isolator switches that stopped isolating years ago, and bonding absent where the zones demand it. If your report flagged the shower circuit, the fix is usually a day or less, and it's often the single item standing between an unsatisfactory report and a satisfactory one.
Shower dead, tripping, or ancient?
Send a photo of the unit and the fuse board — often enough for a fixed replacement price without a visit.
What a shower install costs
These are estimates, not quotes. Final costings always follow a free site inspection — and jobs often come in under the estimate, never over without you agreeing it first.
Like-for-like replacement: £160–£300. New circuit or upgraded supply to a higher-rated unit: £300–£550, depending on the run from the board. Indicative, confirmed from two photos: the shower's rating plate and your consumer unit.
Can I replace an 8.5kW shower with a 10.5kW?
Only if the cable and protection are up to it, which is a measurement, not a maybe. Sometimes they are, and it's a swap; when they're not, the honest job is the new circuit, and I'll show you the numbers that say so.
Does an electric shower need its own circuit?
Yes, its own dedicated circuit from the board with RCD protection and a local isolator. A shower teed off anything else is a finding waiting for an inspection.
Can a plumber fit an electric shower?
The water side, yes. The electrical side is notifiable-adjacent, safety-critical work in a special location, and the plumber who's honest about that will tell you the same. On my jobs the two trades are sequenced so neither waits on the other.
