gledhill benchmark BoilerMate A-Class OV Series Design, Installation And Servicing Instructions page 24

2.0 INSTALLATION
2.2 INSTALLATION
It is normally envisaged that the feed and
expansion cistern will be located in the same
cupboard as the BoilerMate appliance itself to
maintain a dry roof space.
The cold feed/open vent pipework assembly
(as supplied) should be used if it is intended
to install the F & E cistern directly on top of
the appliance
However, if it is necessary to locate the cistern
in the roof space (or on a higher floor) the
cold feed/open vent pipework assembly (as
supplied) should be used to connect to the
F & E cistern and pipework site run by the
installer to connect this to the appliance.
Obviously, any pipework in the roof space and
the feed and expansion cistern will need to be
adequately insulated to protect against frost
damage.
Combined feed and open vent pipe
arrangements must not be used.
No valves should be fitted in the safety open
vent which must be a minimum of 22mm
copper pipe or equivalent.
The overflow/warning pipe shall have a
continuous fall, be fitted to discharge clear
Cold feed / open vent
of the building and be sited so that any
pipework assembly
Overflow can be easily observed. It shall also
(as supplied)
be installed in a size and material suitable for
use with heating feed and expansion cisterns in
accordance with BS 5449 and should not have
any other connections to it.
Interconnecting
Pipework
(By Installer)
Page 24