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Hot And Cold Water
An important feature of the BoilerMate is that hot water can be supplied directly from
the mains at conventional flow rates without the need for temperature and pressure
relief safety valves or expansion vessels. This is achieved by passing the mains water
through a plate heat exchanger. The outlet temperature of the domestic hot water is
maintained by a printed circuit control board, which controls the speed of the pump
circulating the primary water from the store through the plate heat exchanger.
Pressures
A schematic layout of the hot and cold-water services in a typical small dwelling is
shown below. BoilerMate SP will operate at mains pressures as low as 1 bar and as
high as 5 bar although the recommended range is 2-3 bar dynamic at the appliance.
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 fitted in the system, a pressure limiting
(reducing) valve set to 3 bar will be required.
If you encounter a situation where the water pressure is adequate but flow rates are
poor please contact our technical helpline for details of an effective solution.
Inline Strainer/Flow Regulator
Each BoilerMate is fitted with a strainer and flow regulator on the cold mains supply
connection. If the supply pressure is less than 2 bar or if all taps are provided with flow
regulators the flow regulator on the cold inlet should be removed.
Check valve locations
No check valve or similar device should be fitted on the cold-water supply branch
to the BoilerMate.
Water Hardness
The Domestic Building Services Compliance
Guide (2013) provides more detailed
information on the guidance contained in
Approval Documents L1A and L1B, guidance
to the Building Regulations. The recommended
minimum standards specify that “where
the mains water hardness exceeds 200ppm
provision should be made to treat the feed
water to water heaters and the hot water circuit
of combination boilers to reduce the rate of
accumulation of lime scale”.
To comply with this requirement the hardness
of the mains water should be checked by the
installer and if necessary, the optional kit,
BCK008, electronic scale inhibitor should be
requested at the time of order for hardness
levels between 200 and 300 ppm (mg/l).
Alternatively, the inline scale inhibitor XB043,
can be ordered which is fitted in the cold water
pipework prior to the DHW PHE.
Where the water is very hard i.e. 300ppm (mg/l)
and above a polyphosphate type, inhibitor
should be fitted by the installer at a suitable
point in the cold water supply to the appliance.
INSTALLATION
DOMESTIC HOT WATER
Warning/
overflow
pipe
MCWS
Servicing
valve
Safety/open vent
Shower
Expansion/
cold feed
Second
dwelling
Pressure limiting valve
NOT REQUIRED at
pressures below 5 bar
unless any components
have a lower
maximum working
pressure
Double check valve
NOT REQUIRED unless
pipe supplies more
than one dwelling
‘a’ - flow regulator recommended for
better balance of hot and cold
water supplies
MCWS
supply
pipe
Sink
H C
a a
SV
a a
a a
Bath
H C
Hand basin
H C
WC - fitted
with BS1212
ballvalve
C
Typical hot and cold water distribution
BOILERMATE
Check valve
NOT REQUIRED unless
chemical water
treatment unit is fitted
If an auto fill top up is fitted, a check valve
can be installed here to prevent
stagnent water from this pipe back flowing
into the mains cold water supply
a
Top up cistern
Summary of Contents for BOILERMATE OV PP
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