Buying, selling or running a home – everything you need to know about your home and garden!

Power showers

Power showers offer all the advantages which make them most people’s ideal shower. The water flow is assisted by a pump, giving a constant flow of water at a steady temperature and an even pressure in all circumstances without the need for a substantial head (vertical height between the water storage tank and the shower sprayhead). In most cases, just 75mm-225mm (3″-9″) is all that’s needed.


The pump can boost the pressure of water from the hot and cold tanks, but not from the mains direct.

Cold water: It’s best if this comes direct from the cold water tank, rather from a branch pipe which also serves other outlets such as baths, sinks or toilets.

Hot water: A straightforward connection between the pump and the cylinder may lead to the pump sucking in air from the cylinder vent pipe and thus creating a spluttering flow of water. To counteract this, ensure that the connection is made with a Surrey flange or an Essex flange.

Depending on how your hot water storage tank is heated, you’ll need to take one of the following precautions:

  • If it’s an electric immersion heater, you’ll need to ensure that it’s filled via a dedicated feed (not going to any other outlet) and that the gate valve is fully open. Otherwise there’s a risk that the top of the cylinder may run dry and cause the heater element to burn out.
  • If it’s heated from a boiler, you’ll need to fit a thermostat, otherwise if the water’s too hot this can be another cause of spluttering.

Electricity: As usual with electrically-powered devices in the bathroom, the main switch should be either outside the bathroom altogether or mounted on the ceiling.

The pump

There are three different basic types of power shower, depending on where the pump’s housed:

  • The simplest is the all-in-one type, where the pump is an integral part of the mixer unit in the shower cubicle.
  • You can also find installations where the pump is a separate unit providing pressure for both hot and cold feeds (a twin impeller pump). This sort of pump may be the only pump or a booster for an all-in-one power shower. A common location for this kind of pump is next to the hot water cylinder, on or near the floor to ensure that the pump stays full of water at all times.
  • Some pumps are designed to work at a high level where space at a lower level is limited. If that’s the case, the best solution is generally to fit a single impeller pump between the mixer and the shower head, so that the hot and cold water are already mixed by the time they reach the pump.

Whichever form of shower you’ve got, remember that if there’s any chance that the shower head can dangle in dirty water, you’ll have to fit non-return valves in the cold and hot water feed pipes to ensure that dirty water can’t be sucked back into the system.