Electric Shower Replacement Project in Slough

We completed an electric shower replacement in Slough, swapping a failing unit for a new one on the existing water feed and electrical supply. A like-for-like job usually takes two to four hours, provided the existing cable and protective device suit the new shower. If they don’t, the job grows, and checking that is the most important part of the visit.

An electric shower heats cold mains water as it passes over an internal element. The usual faults are:

Repair or replace? Descaling the head and filter is worth trying when reduced flow is the only problem. We recommend replacement when the element has failed on an older unit, the casing is cracked or leaking, the RCD keeps tripping, or the owner wants a higher-powered or thermostatic model. That is professional judgement, not a regulation.

An electric shower is a high-load appliance. It should sit on its own circuit from the consumer unit, with a suitably rated MCB and RCD protection, and a double-pole isolator (usually a ceiling pull-cord) outside the shower zones. The cable must be large enough for the shower’s rating, and higher-rated showers need heavier cable. The manufacturer’s instructions and BS 7671, the UK wiring regulations, set the exact requirement.

This is not a DIY electrical job. Water and mains electricity in the same room leave little margin for error.

Electric showers need a mains cold feed. A bathroom supplied only from a loft tank is generally not suitable without a separate mains pipe.

Running cost example: a 9.5 kW shower used for 8 minutes draws about 1.27 kWh (9.5 x 8 / 60). Multiply that by your own unit rate to see the cost per shower. A shorter shower saves more than a lower-rated unit, which simply gives a cooler one.

Published 2026 UK price guides give a broad picture for a like-for-like swap:

The price rises when a new circuit or heavier cable is needed, when the new shower has a higher rating than the old one, when an isolation valve or pipework has to be added, or when the wall needs repair.

Tips from the job: photograph the old wiring and pipework before disconnecting anything; check the cable insulation at the terminals for discolouration; descale or replace the shower head every year or two; and run the shower at full power for several minutes at the end, because some faults only show under sustained load.

Slough has a mix of 1930s semis in areas such as Cippenham and Langley, post-war housing in Britwell and Chalvey, and newer flats around the town centre. Older homes may have original wiring, a small consumer unit or a shower circuit added decades later, and these need closer checking. Flats can have restricted access and a different water pressure from a house. Hard water makes limescale a common cause of failure across the area.

Call one if the shower is leaking, trips the RCD or smells of burning (switch it off at the isolator and consumer unit first), if you want a higher-rated unit, if you don’t know the age or rating of the cable, or if you need a certificate for insurance, a landlord’s records or a sale. Our plumbing services covers the work OnTime Plumbers does.

Can I replace an electric shower myself? The water connection may be within a competent DIYer’s reach, but the electrical connection should be made and certified by a qualified person.

How long does it take? Typically two to four hours for a like-for-like swap, longer if the circuit needs checking or upgrading.

How much does it cost in Slough? UK guides put a like-for-like swap at roughly £250 to £600 installed, with labour alone from about £100 to £300.

Can I fit a higher kW shower than my old one? Only if the existing cable, protective device and consumer unit can safely support it. Otherwise the circuit must be upgraded.

Why is my electric shower only lukewarm? Usually limescale on the element or head, a failing element, or cold incoming water in winter.

Does it need Building Regulations approval? A like-for-like replacement on a suitable existing circuit is generally minor work. A new circuit is notifiable under Part P in England. Confirm with your installer.

Is it safe to use a shower that trips the RCD? No. Isolate it and have it checked first.

OnTime Plumbers replaces electric showers, from straightforward like-for-like swaps to upgrades that need circuit checks. Tell us the make and rating of your current shower and what you want to replace it with, and we’ll confirm the job and the price before we start.

Call OnTime Plumbers: 08000 584799 | Plumbing services