Benchmark SysteMate 125 97-317-26, Design, Installation And Servicing Instructions, Page: 10 / 44

Page 10
1.3 SYSTEM DETAILS
Hot and Cold Water System
General
A schematic layout of the hot and cold water services in a typical small dwelling is
shown below. SysteMate 2000 will operate at mains pressures as low as 1 bar and as
high as 5 bar although the recommended range is 2-3 bar. If the manifolds (available as
an optional extra) are being used the inlet pressure to the manifold must be a minimum
of 2 bar. It is also important to check that all other equipment and components in
the hot and cold water system are capable of accepting the mains pressure available
to the property. If the mains pressure can rise above 5 bar or the maximum working
pressure of any item of equipment or component to be fi tted in the system, a suitable
pressure limiting (reducing) valve will be required.
If you encounter a situation where the water pressure is adequate but fl ow rates are
poor please contact our technical helpline for details of an effective solution.
Note: Each SysteMate 2000 is fi tted with a strainer and fl ow regulator on the cold
mains supply connection. If the supply pressure is less than 2 bar or if the manifolds
(available as an optional extra) are being used or if all taps are provided with fl ow
regulators the fl ow regulator on the cold inlet should be removed.
No check valve or similar device should be fi tted on the cold water supply branch to
the SysteMate 2000.
To comply with the Benchmark Guidance Note for Water Treatment in Heating and Hot
Water Sytems the installer should check the hardness level of the water supply and
if necessary fi t an in-line scale inhibitor/reducer to provide protection to the whole
of the domestic water system. See Appendix C for a copy of the relevant part of the
Benchmark Guidance Note.
1.0 DESIGN
0RESSURELIMITINGVALVE./4
2%15)2%$ATPRESSURES
BELOWBARUNLESSANY
COMPONENTSHAVEALOWER
MAXIMUMWORKING
PRESSURE
3ECOND
DWELLING
-#73
SUPPLYPIPE
3INK
(AND
BASIN
7#
FITTEDWITH
"3
BALLVALVE
"ATH
3-
3CALEINHIBITOR
)&2%15)2%$
3HOWER
(
A A
A
A
A A A
#
( # ( #
#
36
#HECKVALVE./42%15)2%$UNLESS
CHEMICALWATERTREATMENTUNITISFITTED
gAg
FLOWREGULATORRECOMMENDEDFORBETTER
BALANCEOFHOTANDCOLDWATERSUPPLIES
$OUBLECHECKVALVE./42%15)2%$UNLESS
SUPPLYPIPESERVESMORETHANONE
4YPICALHOTANDCOLDWATERDISTRIBUTION
2EMOTE
&%CISTERN
7ARNINGOVERFLOW
PIPE
#OLDFEED
EXPANSION
-AINSMAINS
SUPPLY
/PEN6ENT
%XPANSION
6ESSEL
Note: The diagram above shows the F & E cistern with a ballvalve and warning/overfl ow
pipe which can be fi tted if required. However, the standard preferred arrangement
is for the cistern to be manually fi lled from a temporary hose connection fi tted with
a double check valve.
When specifying this appliance we would
recommend that for hardness levels above
200ppm (mg/l) a hard water appliance is used.
For hardness levels above 280ppm (mg/l) we
would recommend that some form of in-line
scale inhibitor/reducer is recommended by one
of the water treatment companies listed in the
Benchmark Guidance Note (See Appendix C).
The hot water fl ow rate from the SysteMate
2000 is directly related to the adequacy of the
cold water supply to the dwelling. This must
be capable of providing for those services,
which could be required to be supplied
simultaneously, and this maximum demand
should be calculated using procedures defi ned
in BS 6700.
If a water meter is fi tted in the service pipe,
it should have a nominal rating to match the
maximum hot and cold water peak demands
calculated in accordance with BS 6700. This
could be up to 80ltr/min in some properties.