Boosting
the pressure of your mains water supply
We are frequently asked
if it is possible to use a pump to boost the pressure of a poor
mains water supply.
The simple answer is
yes technically it is not difficult and requires only a “Jet”
type pump like the JCR models which have an internal arrangement
that allows them to operate with the limited flow of water available
from the main. Controlled by a FLO-SENSE switch (or BRIO controller
if you have a combi-boiler) this would give automatic pressure
boosting.
This system increases
the pressure at the taps but cannot significantly increase the
water flow. It may however give a higher flow at the taps by
overcoming the losses caused by the pipework within the property
and the taps etc themselves.
There is however another
major problem…
The Water Bye-laws
in the UK do not permit the direct connection of a pump to
the mains supply. Even a pressure washer bought from the
Garden Centre to clean your block paving is technically illegal.
The correct way to solve the problem of low water pressure is
therefore to install a break tank.
The purpose of a break
tank is to catch the water from the mains, and the faster it fills,
the smaller the tank can be. The ideal position is close to the
incoming main (stoptap) and as low down as possible – the greater
the height, the slower it will fill. It should have a low pressure
or fast fill ballvalve to minimise restriction to flow and be
fitted with the manufacturers lid and vent kit.
To work out the size
you must measure the incoming flowrate and compare this with your
rate of use. Measure the flow you get from the kitchen tap (or
the nearest tap to the main) turned on fully – time the filling
of a container of known size to get the flowrate. To work out
use it may help to know that a power-shower will use about 10
Litres/min, an electric shower about 5 L/min, and a tap 5 – 10
L/min depending on size. Filling the bath may be the biggest
problem if your cold bath tap is connected to the mains. Maximum
use in an average house is rarely more than 20 L/min. and then
only for short periods. The bigger the tank you can fit, the
better.
You may wish to consider
taking a drinking supply directly to the kitchen tap so that there
is no risk of drinking water becoming contaminated in a large
storage tank
The outlet from the
tank to the pump should be 22mm min. diameter and sited on the
side near the bottom (to allow any silt or other debris to fall
to the bottom of the tank and not enter the pump) and be away
from the fill ball valve. The pump should be positioned near
to and below the tank, and sharp bends in the pipe should be avoided,
especially immediately before the pump. Fit a good quality “full
bore” valve (quarter turn lever ball valves are ideal) before
the pump for maintenance purposes. The pump will require a spur
fused at 5A.
Pump
model 3CRm80 was designed for domestic water supplies and normally
has the best characteristics for the application.(These pumps
are ideal for replacing Aquapower pumps or Superpro pumps.) It
is also possible to use the JCR jet pumps, particularly if the
pipework in the building is known to be restricting. Check to
see if there are any devices on the system that have a pressure
limitation (Combi boilers often have a pressure relief system
set at around 3 bar) as this will affect the choice of pump, and
may require a pressure reducing valve to be fitted.
The BRIO controller
fits on the top of the pump and makes the system fully automatic.
It requires no adjustment or service once installed. It also
incorporates “dry run protection” and will stop the pump before
damage occurs should the tank run dry for any reason.
If
you would like to discuss your system or require help in selecting
the best pump please call us on 0845 130 3300 to discuss the options.
|