A shower that runs hot then cold, dribbles instead of sprays, or leaks into the room below is rarely fixed by guessing at parts. The first question is what kind of shower you have, because an electric shower, a mixer on a combi boiler and a pumped shower fed from a loft tank fail in different ways and need different replacements. Voltify Contractors carries out shower repairs and shower installation across East and South-East London, from Canary Wharf, Stratford and Bow to Canning Town, Greenwich, Woolwich and Barking, starting with that question every time.
This page covers repairing an existing shower and fitting a new or replacement one. If the shower is part of a wider refit where the bath, basin and toilet are changing too, that is a larger bathroom plumbing job, and everything else sits under our plumbing services.
Which Shower Do You Have?
Look at where the water is heated and whether the shower has its own power. The answer decides almost everything that follows.
| Shower type | How to recognise it | What it depends on |
|---|---|---|
| Electric shower | A box on the wall with its own controls, a cold-water pipe going in and a pull-cord switch nearby | A dedicated electrical circuit sized for its kW rating, and adequate mains cold-water pressure |
| Mixer shower (bar or concealed valve) | Hot and cold pipes go into a valve on or behind the tiles; no box or pull cord | Balanced hot and cold supply from a combi boiler, unvented cylinder or tank-fed system |
| Power shower / pumped shower | A mixer with an integral pump, or a separate pump near the hot-water cylinder | A gravity (tank-fed) system; pumps must not draw directly from the mains |
| Digital shower | A control panel in the shower with a processing box hidden in a cupboard or loft | Power to the box and a supply that suits the specific model |
If you’re unsure, a photo of the shower, the controls and anything visible in the airing cupboard or loft is usually enough to tell.
Shower Repairs: What the Symptoms Usually Point To
These are the patterns most often behind common faults. They narrow the search rather than confirm it; the cause is only certain once the shower has been looked at.
- Temperature swings when another tap is used — common on mixers where the hot and cold pressures are unequal, or where a thermostatic cartridge is scaled or worn.
- Weak or uneven spray — a limescaled head or hose is the simplest cause; on electric showers, low mains pressure or a blocked inlet filter; on pumped showers, a failing pump.
- Shower head drips after it’s turned off — a worn cartridge or valve seal on a mixer, or a solenoid valve fault on an electric unit.
- Electric shower runs only cold, or cuts out — often a thermal cut-out doing its job because of scale or low flow, though a heating-element or supply fault is also possible.
- Pump noisy, surging or not starting — air in the supply, a blocked filter, or a pump nearing the end of its life.
Stop using an electric shower straight away if you can smell burning, see scorching or melting around the unit, its pull-cord switch or the ceiling above, or if it trips the circuit repeatedly. Leave it switched off at the isolator until it has been checked. Diagnosing and repairing the supply itself is electrical work, carried out through our electrical services.
Electric Shower Repair or a New Unit?
An electric shower is a small water heater with a handful of parts that wear out: the heating element, the thermal cut-out, the pressure relief device, the solenoid valve that opens and closes the flow, and the switches behind the controls. When one of those has failed and the rest of the unit is sound, replacing the part is usually the sensible repair.
A new unit is often the better choice when:
- the model is discontinued and genuine parts can no longer be found;
- several parts have failed at once, or the inside is heavily scaled;
- the casing is cracked, or there is scorching around the terminals;
- the cost of the parts comes close to the cost of a replacement unit.
Because an electric shower is both a water fitting and an electrical appliance, the supply cable, the isolator and the circuit protection are part of the check, not an afterthought. Voltify Contractors covers plumbing and electrical work, so the water side and the electrical side can be looked at together rather than passed between two trades. If a replacement is the answer, the section on swapping to a more powerful electric shower below explains why the kW rating matters.
A Leak Below the Shower Is Often Not the Shower
When a ceiling stain appears under a bathroom, people tend to blame the valve. More often the water is escaping somewhere around the enclosure while the shower is in use:
- failed or mouldy silicone where the tray or bath meets the wall;
- a cracked tray, or one that flexes because its base was never properly supported;
- a loose or perished waste seal under the tray;
- grout that has cracked and let water behind the tiles;
- a screen or door seal that sprays water past the edge of the tray.
Stripping and renewing silicone or replacing a waste seal is a routine plumbing repair, but it only lasts if the tray underneath is solid. A useful clue: if the leak only shows while someone is showering, the enclosure or waste is the likely route. If the patch stays damp even when the shower hasn’t been used, a supply pipe or the valve connection behind the wall is more likely, and it may need tracing as a hidden leak. Water coming through a ceiling near a light fitting should be treated as urgent — if it’s safe to reach, switch off the lighting circuit at the consumer unit, and see our emergency plumber page.
Shower Installation: What Decides the Job
A like-for-like swap on an existing supply is usually the most contained type of shower installation. Changing the type of shower, or putting one where there wasn’t one before, is where most of the planning goes.
Your hot-water system
Mixer showers need both hot and cold at similar pressures. A combi boiler gives mains-pressure hot water but a limited flow rate, so a large rainfall head may disappoint. A tank-fed system has low pressure unless the shower is pumped. Check the minimum pressure on any shower you’re thinking of buying, and tell us what system you have when you get in touch.
Swapping to a more powerful electric shower
Electric showers are rated in kilowatts. Fitting one with a higher rating than the old unit can mean the existing cable and circuit protection are no longer suitable, so the electrical side is checked before any work is agreed. Replacing with the same or a lower rating on a sound circuit is normally simpler.
Exposed or concealed valve
An exposed bar valve sits on the tiles and is easier to fit and service later. A concealed valve looks tidier but means opening the wall and making it good again afterwards, which is agreed before work starts. On a stud wall, access to the back of the valve is worth planning in.
The tray, waste and enclosure
New trays need a firm, level base and a waste that falls properly to the drain. Where a shower goes over a bath, the screen, bath edge and wall must be sealed so water can’t track behind the panel. Walls around a new enclosure also need to be suitable for constant wetting before they are tiled.
Things outside this service
Work on a boiler, or on an unvented hot-water cylinder itself, needs a suitably qualified specialist — for a gas boiler, a Gas Safe registered engineer. We’ll tell you if what you want depends on changes there.
How a Shower Visit Runs, Step by Step
Whether the shower needs a new cartridge or the whole unit is coming off the wall, the order of work stays the same, so nothing is replaced on a hunch.
- Before anyone arrives: you send a photo of the shower, its controls and, if you have one in mind, the make and model of the replacement.
- Type and supply first: the shower type is confirmed, then the water pressure and flow, and on an electric shower the kW rating against the existing circuit.
- Isolate and test: water and, where relevant, power are isolated before the unit or valve is opened, and the fault is traced rather than guessed at.
- Agree the fix: you are told whether a part, a service or a replacement makes sense, and what it involves, before any parts go in.
- Run it and check the seals: the shower is run at different settings, the temperature and spray are checked, and joints, the waste and the enclosure edges are looked at for weeping.
If the weak flow is not just in the shower but at every tap, the cause is more likely to be the supply into the property. Our guide to low water pressure causes explains what to check first.
Getting a Shower Repaired or Fitted
Send a photo of the shower and its controls, what it’s doing or what you’d like fitted, and the make and model if you’ve already chosen a replacement. For repairs, the documented minimum call-out is £80 for the first hour during standard hours, 7am–5pm Monday to Friday. Replacement cartridges, pumps or parts, extra time for seized fittings, and any making good around a concealed valve are added to that. New installations are quoted once the existing supply and wall construction are known. Contact Voltify Contractors to talk it through, or check the areas we cover first.
