Worcester benchmark ZWB 7-25 R 25 HE Design, Installation And Servicing Instructions page 56

General notes
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 BS6798.
Notwithstanding the requirements of BS6798, there is no need
for ventilation openings to be provided in the compartment
because of the low heat loss from the casing.
Do not allow the flue terminal fitted on the outside wall to become
obstructed or damaged.
Pump
The pump will have been set by the manufacturer and must not be
manually re-adjusted.
6 720 610 577 GB (03.11)
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