Doc No. 700025 Page 13 of 32
If the flue passes through a wall, ceiling, or
roof made from combustible material then it
has to be sleeved so as to provide a minimum
of a 50mm void between the exterior of the flue
and the internal wall of the sleeve. A minimum
of 50mm must be maintained as a clearance
distance to all other combustible materials.
The manifold should be supported by chain,
stainless steel flexible wire, or other flexible
means from the roof structure to allow
movement caused by thermal expansion.
The maximum distance between supports is
1.5m for horizontal runs.
Wall bands are not load bearing and give
lateral support only. If used, wall bands should
be fitted every 3m on vertical runs to ensure
the system is rigidly held. The system should
be braced immediately below passing through
the roof line to ensure the flashing does not
suffer lateral pressures.
The maximum height unsupported above the
roof line is 1.5m. Where a joint is above the
roofline it should be determined that in extreme
wind conditions this joint would not be over
exerted. If there is any doubt then a guy wire
should be used. Beyond this guy wires should
be installed every meter.
The POCED is capable of withstanding its own
weight when installed in accordance with these
instructions and the Regulations shown below.
The exhaust flue should be adequately
supported from the building structure and
installed in accordance with the British
Standard Code of Practice BS 5440: Part 1: -
Installation and maintenance of flues and
ventilation for gas appliances of rated input not
exceeding 70kW net (1st, 2nd and 3rd family
gases), and the flue system manufacturers
instructions as supplied with the flue.
See reference BS 6896: Condensate drain
pipes must be protected against the effects of
freezing.
1.9.3 Condensation
When designing the flue system the prevention
of the formation and entrapment of
condensation must be a key consideration.
1.9.4 Flue Connection
All pipe lengths and flue gas carrying
components are joined together by a twist lock,
bayonet system. The system should be installed
with the visible male collar pointing upwards, this
is reaffirmed by the directional arrow pointing
upwards, indicating the directional flow of flue
gases. Taping of the joints is unnecessary.
1.9.5 Ducted Air
To prevent water ingress on VTC models it is
necessary to fit ducted air to the burner via the
flange shown in Fig.7 on page 15 of this
document
The ducted air flange is fitted with a flexible tube
and secured with a hose clip as shown in the
picture below.
The other end of the flexible hose connects with
the solid tube of the fresh air intake and secured
with a hose clip.
For dirty or polluted environments it is
recommended that VT models are fitted with
ducted fresh air.
Flange part No.
201447
and 3 off screws part
No.
201091
are available from the manufacturer.