Types of shower in the UK: how each works and what fits

The main types of shower in the UK are electric showers, which heat cold mains water in their own unit, and mixer showers, which blend hot and cold water from your boiler or cylinder. Power, pumped and digital showers are variations on the mixer. Which you can have depends on your hot water system.

This guide shows how to tell which shower you have, what each type needs, from wiring to water pressure, and which shower heads fit each one. If you are weighing up a filter head, our complete guide to filter shower heads in the UK covers the rest.

We sell a handheld filter shower head, so every rule and figure here links to its source.

Types of shower in the UK: the short answer

The types of shower in UK homes come down to five: electric, mixer, power, pumped and digital. Each needs a different supply, so the hot water system in your home decides which you can have.

At the end of each sits a handheld head on a hose, a fixed head on an arm, or both. How handheld and fixed shower heads compare is covered in its own guide.

How to tell what type of shower you have

Telling what type of shower you have takes a minute: look at the unit on the wall, then at where your hot water comes from. These clues cover most UK bathrooms.

• Electric: a box on the wall with its own power and temperature controls, usually with a pull-cord or switch nearby. It heats water even when the boiler is off.
• Mixer: a bar valve on the wall, or controls set into it, fed by hot and cold pipes. With no hot water in the system, it runs cold.
• Power: a mixer-style unit with a pump inside, which you may hear running.
• Pumped: a mixer with a separate pump fitted elsewhere, for example near the hot water cylinder.
• Digital: a control panel or remote, with the mixing done in a separate unit.

Then look for tanks. A cold water tank in the loft and a hot water cylinder in a cupboard point to a gravity-fed system. A cylinder with no loft tank suggests an unvented system, and a boiler with no tanks at all is usually a combi.

Gravity-fed, combi or unvented: which hot water system do you have?

The hot water system behind a shower sets its pressure and how much hot water it can draw, so it matters as much as the shower itself. UK homes usually have a gravity-fed system, a combi boiler or an unvented cylinder.

Gravity-fed (open-vented)

Which? explains that a heat-only boiler, also called a conventional or regular boiler, connects to a water tank to provide hot water. The most common open-vented setup needs a cold-water feed and expansion tanks in the loft. Pressure at the shower comes from the height of the tank above it, so it can be low, especially upstairs.

Combi boiler

A combi boiler connects directly to the mains cold supply and heats water on demand, with no tanks. Which? notes that it is limited by mains pressure, and that the flow reduces when it supplies hot water to two or more places at once, so it suits one shower at a time.

Unvented cylinder

An unvented system stores hot water in a sealed cylinder fed at mains pressure. Which? says a system boiler needs a hot-water cylinder but, unlike a conventional boiler, no cold-water tank. In England, Approved Document G treats installing an unvented hot water system as notifiable building work. An installer registered with a competent person scheme for that work can self-certify it instead of notifying building control in advance.

Whatever the system, the mains supply to your home has a floor. Discover Water describes the minimum standard as 10 metres head at a boundary stop tap, with a flow of 9 litres per minute. It notes that some modern heating appliances and showers will not work below certain pressure levels.

Electric showers: how they work and what they need

An electric shower heats cold mains water in its own unit as the water flows through, so it gives hot water without the boiler. It needs a cold supply with enough pressure, its own electrical circuit and a qualified electrician to install it.

Living Made Easy, the Disabled Living Foundation's advice site, explains that electric showers have only a cold water feed and need a minimum water pressure, so they almost always run from the mains. Their element heats the water like an electric kettle. The temperature may fluctuate if the flow is reduced, for example when someone else runs a tap.

Electrical Safety First says an electric shower must be installed by a registered competent electrician and supplied on its own circuit. It adds that all circuits in or passing through bathrooms are now required to be protected by an RCD.

On GOV.UK, the guide to when you need building regulations approval lists changing electrics near a bath or shower among the jobs that may need it. You don't need approval yourself if you use someone registered with a competent person scheme. This covers England; Scotland, Wales and Northern Ireland have their own rules.

Which heads fit an electric shower?

An electric shower usually feeds a handheld head on a hose from the outlet on the unit. Some manuals allow only the head and hose the maker supplies or specifies, because flow at the outlet affects the temperature. Don't fit a filter head, ours included, unless your shower's manufacturer confirms in writing that a filter head can be fitted to your model. Our guide to using a filter shower head with an electric shower quotes two makers' manuals and gives a five-minute check.

Mixer showers: thermostatic, manual or digital?

A mixer shower blends hot water from your boiler or cylinder with cold water in a valve, so it runs on supplies you already have. Mixers come in thermostatic, manual and digital versions, and all of them depend on the hot water behind them.

Thermostatic mixers

Living Made Easy describes a thermostatic mixer as using pre-heated water from your boiler or hot water tank, with controls that automatically compensate for changes in water pressure. So if someone turns on a cold tap elsewhere in the house, the shower shouldn't turn suddenly hot. Some models shut off completely if either the hot or the cold supply fails.

Manual mixers

A manual mixer sets the blend of hot and cold with a simple control and has no thermostat to correct it. That keeps it simple, but the temperature can shift when another tap or appliance draws water.

Digital showers

A digital shower is a mixer with electronic controls. Living Made Easy notes that digital controls let you programme your temperature and include thermostatic control, and that a second remote control unit is usual, which can be useful for a carer. Because the controls are electronic, a digital shower needs an electricity supply as well as hot and cold water.

Bath shower mixers

Some bathrooms have no separate shower valve: a bath shower mixer tap feeds a handheld head on a hose. Hang the head where it can't dip into the bath water or reach the toilet; our guide to fitting a shower head and hose explains why, and how.

Power showers and pumped showers: boosting a gravity-fed system

A power shower is a mixer with a pump built in, and a pumped shower is a mixer boosted by a separate pump. Both raise the flow from a system with a hot water cylinder, and both need planning, because pumps connected to the water supply come with rules.

They don't suit every home. Which? says combi boilers aren't usually compatible with a shower that has a powerful electric pump, so a home with a power shower usually needs a heat-only or system boiler instead.

In England and Wales, regulation 5 of the Water Supply (Water Fittings) Regulations 1999 covers any pump or booster drawing more than 12 litres a minute, connected directly or indirectly to a supply pipe. Anyone planning to fit one must give notice to the water company and must not begin without its consent, so ask your installer to handle it.

A pump also needs an electricity supply, so a power or pumped shower combines plumbing and electrical work. The heads and hoses should be ones the shower's manual allows.

Which shower heads fit which type of shower?

Most showers take one of two kinds of head: a handheld head on a flexible hose, or a fixed head on an arm. The type of shower decides how free your choice is, and its manual has the last word.

Hose connections vary between showers, so look at yours before you buy, and keep the old head and hose in case you need to refit them. Once you know what fits, our guide on how to choose a shower head covers pressure, spray patterns, size and cleaning.

The Waterhush Shower Kit is a handheld filter head on its own 1.5 m hose, so it needs a shower with a hose outlet. We don't yet have a confirmed thread size, pressure or flow figure for it, so contact us if you're unsure it will fit. It is not for electric showers unless your shower's manufacturer confirms in writing that a filter head can be fitted to your model. Waterhush reduces free chlorine; that is the one claim we make.

Is it right for your shower? Check in three questions.

What a guide can't tell you about your shower

What a guide can't tell you is exactly what your own shower and system can take. Models, installations and manuals differ, so the label on the unit and its manual beat any general description.

• Your model: find the make and model on the unit and read its manual, especially for electric, power and digital showers.
• Your pressure: the pressure at the shower depends on your pipework and tanks as well as the mains supply, and a plumber can measure it.
• Wiring and pumps: electrical work near a shower and pumps on the water supply come with rules, so leave them to qualified installers.

This guide describes the common types in UK homes, not every product or installation.

The bottom line

The main types of shower in the UK are electric, mixer, power, pumped and digital, and your hot water system decides which you can have. Electric showers heat cold mains water on their own circuit; the others draw on your boiler or cylinder. The main limit: only your shower's manual confirms which heads it takes. Next step: identify your shower and system, then read the manual before you change the head.