Electric showers vs mixer showers: which suits your home

Most UK showers are one of two kinds. An electric shower heats cold water itself, inside the unit on the wall. A mixer shower takes hot and cold water that your home already supplies and mixes them to the temperature you choose. Which one suits you depends on how your home gets its hot water, how strong your supply is, and what electrical supply is already in place.

How an electric shower works

An electric shower is fed only by a cold mains supply. Water passes over a heating element in the unit and comes out warm. It does not use the hot water cylinder or the boiler.

Good points:

• hot water whenever the shower runs, even if the cylinder is cold or the boiler has broken down;
• it does not use stored hot water, so it can suit a second bathroom or an en suite in a busy home;
• no need for a hot supply to the bathroom.

Limits:

• the flow is limited by how much water the element can heat. A higher power rating heats more water, but the flow is still usually lower than a good mixer shower;
• in winter, when the incoming mains water is colder, many electric showers give a lower flow to keep the temperature up;
• limescale builds up in the unit and the head in hard water areas;
• it needs a large, dedicated electrical supply of its own.

How a mixer shower works

A mixer shower has a valve that blends hot and cold water from your existing supplies. The valve can be manual (you adjust the mix) or thermostatic (it holds a set temperature and compensates if someone runs a tap elsewhere). Thermostatic valves are popular in family bathrooms because they reduce the risk of sudden hot bursts.

How well it works depends on your system.

• Gravity-fed (a cold cistern in the loft and a hot cylinder): the pressure depends on the height between the cistern and the shower head. An upstairs shower directly under the loft can be weak. A shower pump can help, but only the right type for a gravity system. See our shower pump sizing guide.
• Combi boiler: hot water at mains pressure, heated as you use it. A mixer shower usually works well if the incoming mains is good and the boiler can supply enough hot water. Do not fit a standard shower pump to a combi.
• Unvented cylinder: stored hot water at mains pressure. Usually gives a strong mixer shower. Again, a standard shower pump is the wrong product.

A mixer valve has to suit the pressures it is fed with. Some valves are designed for low pressure, some for high pressure and some for both, and many need the hot and cold supplies at broadly similar pressures. Read the maker's own page for the pressure range before buying. If you are not sure which system you have, our low water pressure guide explains how to tell.

A power shower is a mixer shower with a pump built into the unit. It is for gravity-fed systems only, for the same reason as a separate shower pump.

Side by side

	Electric shower	Mixer shower
Water supply	Cold mains only	Hot and cold from your existing system
Hot water	Heated in the unit	From the boiler or cylinder
Works if the boiler is off	Yes	No
Typical flow	Limited by the heater's power	Depends on your system's pressure
Electrics	Needs its own dedicated circuit	Usually none, unless it has a pump
Who fits it	Electrician for the supply, plumber for the water	Plumber

Electric showers are electrical work

An electric shower draws a lot of current and needs its own circuit from the consumer unit, sized for that shower, with the right protection. It is also in a bathroom, where the rules on electrical work are stricter.

Some electrical work in homes must be notified under the Building Regulations. In England this is covered by Part P. The GOV.UK page for Approved Document P explains when notification is required. Wales, Scotland and Northern Ireland have their own building regulations, so check the rules where you live. Electrical Safety First recommends using an electrician registered with a government-approved scheme.

In practice:

• a new electric shower where there was none almost always needs a new circuit. That is a job for a qualified electrician;
• replacing an existing electric shower with a more powerful one may need a bigger cable and new protection. Do not assume the old supply is good enough. Ask a qualified electrician to check before you buy;
• like-for-like replacement still involves working on a high-current supply in a bathroom. Unless you are qualified, have an electrician do the electrical side.

We do not give wiring instructions on Leatmere. A plumber can do the water connection, and a qualified electrician should do the supply and test it.

Which should you choose?

• You have a combi or an unvented cylinder with good mains pressure: a mixer shower usually gives the best flow, with no pump needed.
• You have a gravity-fed system with a decent head of water: a mixer shower can work well. With a weak head, a mixer plus the right shower pump, or a power shower, can help.
• You want a shower that works independently of the hot water, or in a room far from the cylinder: an electric shower can make sense, as long as the electrical supply is done properly.
• Your mains pressure or flow is poor: neither is a magic fix. An electric shower needs an adequate cold mains supply too. Check the maker's minimum supply figures and talk to a plumber.

A mixer shower at Wickes

We have not listed electric showers here, because choosing one depends on your electrical supply, which an electrician needs to check first.

We haven't tested this. Figures are as the maker states them (checked 13 November 2026).

Can I replace an electric shower myself?

The water side is ordinary plumbing, but the electrical side is high-current work in a bathroom and may need to be notified under the Building Regulations. Have a qualified electrician check the existing supply and do the electrical work, especially if the new shower is more powerful.

Is a mixer shower better than an electric shower?

Not always. A mixer usually gives a stronger flow on a combi, an unvented cylinder or a well-fed gravity system. An electric shower is independent of the hot water and the boiler, which can suit some homes better.

Why does my electric shower get weaker in winter?

The incoming cold water is colder, so the heater has to work harder to reach the same temperature. Many electric showers reduce the flow to keep the water warm. Limescale in the head can make it worse, so clean the head too.