Checking The Connections; Flue Systems - Worcester ZWBR 7-28 HE plus Installation And Servicing Instructions

Installation
Connecting the flue duct
y Fit flue duct connector onto appliance flue spigot.
y Secure with the two screws supplied.
Fig. 13
y For remaining installation of flue assembly, refer to
the relevant installation instructions.
3.8

Checking the connections

Water connections
y Check that the O-rings or seals are in place before
tightening the connection.
y Turn on the service valves for central heating flow
and return and fill the heating system through a WRC
approved filling loop.
y Check all seals and unions for leaks (testing pressure
max. 3.0 bar as indicated by pressure gauge).
y Turn on cold water service cock and fill hot water sys-
tem (testing pressure max. 10 bar).
y Check all connections for leaks.
Gas supply pipe
y Check that the seal is in place before tightening the
connection.
y Turn off gas cock to protect gas valve against
damage from excessive pressure.
y Check gas supply pipe.
y Release the pressure on the gas supply pipe.
16
3.9

Flue Systems

The only flue systems that may be used are those sup-
plied by Worcester Heat Systems.
The flue system must be installed in accordance with
the requirements of BS5440:1.
Standard 100 mm flue system
The standard concentric flue system provides for a hor-
izontal length of upto 4 m. Full instructions for fitting this
flue are in Subsection 3.9.2 "Installation of the flue".
Alternative 125 mm diameter flue systems
Installation instructions for the alternative flue systems
are sent with the appropriate flue kit.
Systems are available to give a maximum horizontal
length of 13 m (ZWBR 7-28) and 10 m (ZWBR 11-35).
A vertical flue system upto a height of 15 m (ZWBR 7-
28) and 12 m (ZWBR 11-35) is available.
45° and 90° flue bends can be used with a correspond-
ing reduction in flue length of 2 m for each 90° bend
and 1 m for each 45° bend used.
IMPORTANT: Any horizontal flue system fitted to a
condensing boiler must incline towards the appliance at
an angle of 3 % (30 mm per metre length) to prevent
condensate dripping from the flue terminal. This
means that the clearance above the appliance
must be increased to match the duct length.
Refer to fig. 1 on page 5.
6 720 610 597 GB (01.07)