Electric showers are the easiest showers to install in
terms of compatibility with existing water heating
systems and locations throughout the home. They draw
water direct from the mains water supply and heat it as
it is used for showering. It can be used in most
domestic showering applications e.g. over the bath,
shower cubicles, shower rooms etc.
Provides a shower that is independent of the main hot
water heating system in the house, thus reducing the
risk associated with breakdowns.
Can be installed in almost any home throughout the UK
new & old.
Instantaneous shower; it can be used at any time of the
Requires electrical wiring from the shower unit to the
main fuse box.
Flow rate tends to be lower than showers that use the
homes main water heating system, and it will vary
between summer when the incoming water is warm, and the
winter when the flow rate will reduce because the
incoming water is significantly colder.
Cost wise, the installation costs may be higher than
showers that use the homes main water heating system due
to the need for plumbing and electrical work.
Higher kilowatt output showers have gone a long to help
overcome some of the disadvantages of poor flow; (10
kilowatt showers are the equivalent of over 3 emersion
heaters or 10 x 1 kilowatt bars on an electric fire) but
to some an electric appliance fitted in the bathroom is
perceived as a safety risk. This is not the case,
providing it is properly installed, by a trained
professional who knows what he is doing. Electrical
appliances are often associated with water for example
the kettle, washing machine or the electric cooker,
which needs frequent washing.
If this is the shower solution for you make sure its
fitted correctly and use a reputable brand that has an
established reputation within the UK.
Information about the different
types of shower systems...
Electric showers can be used with most domestic water
systems. They are in most cases connected to the mains
cold water supply; the feed pipe should have an
isolation valve. This allows the valve to be turned off
for maintenance if required.
The electrical connections to an electric shower are
covered by many regulations. An electric shower must be
installed on its own circuit s capable of providing the
current necessary and must be rated above 60 amps. An
RCD (residual current device) must be installed as,
either part of your existing fuse board, or separately,
interrupting the circuit to the shower. Connection to
the fuse board should be by means of a MCB (miniature
circuit breaker). Fuse, switch and cable ratings are
also vital and we would suggest that 10mm cable is used
for all installations. This makes upgrading your shower
much easier in the future.
In all cases the circuit should be interrupted by a
double pole pull cord switch with neon on/off indicator
and a mechanical indicator should the neon fail.
Mixer showers are so called because they will mix the
existing hot and cold water, in a special valve, before
it is available at the shower head. They are suitable
for either low or high pressure (check with your
supplier that the mixer valve you buy is suitable for
the system you have). They are available as surface
mounted fixtures, where the pipe work is easily
installed on the top of your existing surface, or flush
mounted, where the valve is seen, but the pipe work is
hidden behind the surface. They are then ideal to
install in a new shower cubicle construction where the
pipes can be built into a wall.
To operate correctly both the hot and the cold water
need to come from a source operating at the same
pressure. Both can come from a mains fed system, (combi
boiler or multi point water heater and cold mains) or
both can come from tank fed water (immersion and cold
storage tank). If one supply must come from high
pressure and one from low pressure, a pressure balanced
mixer valve can be installed.
A mixer shower will not increase the flow of water to
your system. If your water flows from your taps at a
poor rate, this is the rate it will feed the shower.
A drawback to installing a mixer shower is the fact that
it will usually be connected to pipes which supply water
to other points. When the other points are used (taps,
toilet cistern etc) the flow rate to the shower will be
affected. This in turn will affect the temperature of
the water coming out of the shower and, in the case of
the cold being drawn off elsewhere, could lead to
scalding. This can be overcome, with a low pressure
system, by laying separate pipes to the valve from both
hot and cold supplies and making the shower water
independent. You may need to contact a plumber for this
as it will mean installing a special flange in the top
or side of your hot water cylinder. In the case of a
mains fed mixer a thermostatic valve is recommended.
Mixer showers cannot be pumped from a mains pressure
system (combination boilers, multi point heaters) but
they can from low pressure systems. There are mixer
shower valves especially designed for combination
boilers, (pressure balanced mixer shower).
Thermostatic mixer showers
A thermostatic mixer shower incorporates a pre-set
thermostat that will sense a dramatic change in
temperature and rectify the situation. Some advanced
thermostatic mixers will even cut the water off when a
failure in flow is detected. Most thermostatic mixers
also a have a temperature limiting device to stop very
high temperatures being selected by the user.
Power showers are mixer showers with integral pumps
which increase the rate of flow from the shower head.
They can only be installed on low pressure, tank fed
systems. The cold water tank should be no less than 50
gallons acceptable for the shower alone. A dedicated hot
and cold supply is necessary. The water supply must
always be above the unit to ensure that the pump is
always primed and does not have to suck any air.
There are two types of shower pump. The first is a
single impeller pump, with one driving blade which pumps
the water, as it is mixed, to the shower head. This
means of course it must go between the mixer valve and
the head. The easiest place therefore to install the
single pump is in the loft as it must be above the mixer
valve. This can lead to problems with the cold
temperatures in the loft freezing the water and it
cannot be insulated because it needs a free air flow.
For this reason a twin impeller pump was introduced.
This is connected to both the hot and cold water before
they reach the mixer valve and can be sited, ideally, in
the airing cupboard. Most pump manufacturers will
specify that the pump must be within 4 metres of the hot
water cylinder and at least 30mm below the cold tank.
Pumps, as with power showers, must have a dedicated
water supply that serves no other outlets. They must
also be connected to the hot supply with an anti
aeration flange such as an Essex. An electrical
connection is needed and should be taken from a
switched, fused spur on a ring main outside the
bathroom. It will be rated check manufactures
instructions for amps.