Power shower vs electric shower: which one suits your home?
A power shower mixes hot water from your cylinder with cold water from a storage tank and boosts it with a built-in pump, so it gives a strong flow but only works on a gravity-fed system with a tank in the loft. An electric shower takes cold water straight from the mains and heats it inside the unit as it flows, so it works with almost any system and never runs out of hot water, but its flow is limited by how fast it can heat the water. Your water system usually makes the decision for you: tank in the loft and weak pressure points to a power shower, while a combi boiler or unvented cylinder rules one out.
Loyal Plumbers · Updated
Discuss your plumbing workHow each one works
A power shower is a mixer shower and pump in one box on the wall. Hot water comes from a vented hot water cylinder, cold water comes from the cold water storage tank that feeds it, and the pump pushes the mixed water to the head. It uses whatever is in the cylinder, so the length of your shower depends on how much hot water is stored.
An electric shower is connected to the cold mains only. Water passes over a heating element inside the unit, much like a kettle, and comes out warm. It does not touch the boiler or cylinder, which is why many homes keep one as a backup when the boiler fails. The unit needs its own electrical circuit, and the higher the power rating, the more water it can heat at a comfortable temperature.
Which water system suits which shower
This is the question that decides most jobs, so check it before choosing a model. Look in the loft for a cold water storage tank and in the airing cupboard for a copper cylinder with an open vent pipe above it. If you have both, you have a gravity-fed system.
| Your system | Power shower | Electric shower |
|---|---|---|
| Gravity-fed: cold tank in the loft and vented cylinder | Suitable, and usually the biggest improvement in flow | Suitable if the mains pressure is adequate |
| Combi boiler | Not suitable: no stored water to pump | Suitable, often fitted as a backup shower |
| Unvented cylinder (mains pressure) | Not suitable and not needed | Suitable, though a mixer shower usually performs better |
| Flat with a small header tank or shared supply | Depends on tank size and position; needs a survey | Often the practical choice |
A pump must not be used to draw water straight from the mains. The Water Supply (Water Fittings) Regulations 1999 restrict pumps connected to the supply pipe, so power showers and shower pumps are fed from a storage tank. If someone suggests pumping a combi or mains supply, ask them to explain how that complies.
Pros and cons side by side
Neither type is better in every home. The trade-off is flow against independence from the hot water system.
- Flow: a power shower on a gravity system usually gives a stronger, fuller spray; an electric shower gives a steadier but gentler flow
- Hot water supply: a power shower uses stored hot water and can run a cylinder dry; an electric shower heats on demand and never runs out
- Winter performance: an electric shower's flow drops in cold weather because the incoming water is colder and needs more heating
- Independence: an electric shower keeps working when the boiler breaks down; a power shower needs hot water in the cylinder
- Noise: a power shower's pump can be heard while it runs; an electric shower makes a quieter hum
- Installation: a power shower needs suitable hot and cold feeds from the tank and cylinder; an electric shower needs a mains cold feed and a dedicated electrical circuit
- Water use: a power shower can use a lot more water per minute, which matters on a water meter and for how long the hot water lasts
Running costs and water use
An electric shower is paid for in electricity while it runs, and electricity costs more per unit than gas. A power shower's heat usually comes from gas via the boiler, but it tends to use more water, and all of that water has to be heated and, on a meter, paid for. Which is cheaper per shower depends on how long you shower, the flow you set and whether you are on a water meter, so be wary of any blanket claim that one is always cheaper.
If the family often runs out of hot water after two showers, the cylinder size and recovery time matter more than the shower. Our guides to choosing a hot water cylinder size and cylinder recovery time cover that.
Electrical and building rules
An electric shower draws a lot of current, so it needs its own circuit from the consumer unit with the right cable size and protection. A new circuit in a bathroom is notifiable electrical work under Part P of the Building Regulations in England, so it should be done by a registered electrician who can self-certify it, or be approved by building control. Replacing an existing electric shower with one of a higher rating can mean the cable or protective device also has to be upgraded.
A power shower needs a fused electrical supply for its pump, positioned to comply with the wiring rules for bathrooms, plus correctly sized hot and cold pipework from the tank and cylinder. The cold water tank has to be large enough to serve the shower and refill the cylinder.
When a different option is better
Some homes are better served by neither. If you have an unvented cylinder or a combi with good mains pressure and flow, a thermostatic mixer shower on mains pressure usually beats both. If you have a gravity system and like your existing mixer valve, a separate shower pump may do the job without changing the shower itself; see our guide on whether a shower pump suits your water system. And if you are renewing the whole bathroom, it may be worth asking whether the gravity system itself should be replaced; our comparison of unvented and vented cylinders explains that decision.
Getting the right shower fitted
Loyal Plumbers fits and repairs showers, pumps, cylinders and the pipework around them across London and everywhere inside the M25. If you are not sure which system you have, send us a photo of the loft tank, the airing cupboard and your current shower, or call us, and we will tell you which types will work before you buy anything. Where a new circuit is needed, we will say so at the start so it can be planned with a registered electrician.
Common questions
- Is a power shower better than an electric shower?
- On a gravity-fed system, a power shower usually gives a stronger flow. An electric shower is more flexible because it works on most systems and never runs out of hot water.
- Can I have a power shower with a combi boiler?
- No. A combi has no stored water for the pump to draw from, and pumping directly from the mains is restricted. An electric shower or a mains-pressure mixer shower is the usual choice with a combi.
- Does an electric shower need a dedicated circuit?
- Yes. It needs its own circuit from the consumer unit, sized for the shower's power rating. A new circuit in a bathroom is notifiable work under Part P.
- Why is my electric shower weaker in winter?
- The incoming mains water is colder, so the unit has to slow the flow to heat it to the same temperature. Our guide to an electric shower not working covers faults that go beyond that.
- Will a power shower use all my hot water?
- It can. A power shower draws from the stored hot water in the cylinder at a high flow rate, so back-to-back showers can empty a small cylinder.
Sources and further reading
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