Benchmark ZSBR 7-30 RD 430i Installation And Servicing Instructions page 57

General notes
With all mains fed systems the flow of water from individual taps
will vary with the number of outlets operated simultaneously and
the cold water mains supply pressure to the property.
Flow balancing using "ball-o-fix" type valves is recommended to
avoid an excessive reduction in flow to individual outlets.
For further information contact British Gas Technical Services
Department.
Hot and cold flow – Combination Boilers
The flow of water demanded from both hot and cold service out-
lets is dependent upon the mains supply, it may not be possible in
some installations to operate all outlets simultaneously.
Water mains failure – Combination Boilers
If there is a failure of the mains water supply then no water will be
available at a tap or shower until the mains supply is restored. The
appliance will still operate in the central heating mode.
Use in hard water areas – Combination Boilers
In exceptionally hard water areas a device to prevent scale forma-
tion may be fitted. Installation of a scale inhibitor assembly should
be in accordance with the requirements of the local water com-
pany. An isolating valve should be fitted to allow for servicing.
Alternatively the maximum temperature of the domestic hot water
may be reset to about 45 °C which will reduce the risk of scale
formation in these hard water areas.
Ventilation
This is a room sealed appliance and does not require any air for
combustion from inside the house. If the appliance is fitted into a
cupboard or a compartment is built around the appliance after
installation then the compartment must be separated from the
boiler space by a perforated non-combustible partition as
described in BS 6798.
Notwithstanding the requirements of BS 6798, there is no need
for ventilation openings to be provided in the compartment
because of the low heat loss from the casing.
6 720 610 604 GB (03.06) 9