10
Fig. 5
Fig. 6
Building Regulations.
The Institute of Gas Engineers publication (IGE/UP/7)
‘Guide for Gas Installations in Timber Frame Buildings’
gives specifi c advice on this type of installation.
3A.10 INHIBITORS
Vokera recommend that an inhibitor - suitable for use
with aluminium heat exchangers - is used to protect the
boiler and system from the effects of corrosion and/or
electrolytic action. The inhibitor must be administered in
strict accordance with the manufacturers instructions*.
*Water treatment of the complete heating system - includ-
ing the boiler - should be carried out in accordance with
I.S. 813 and the Domestic Water Treatment Association’s
(DWTA) code of practice.
3A.11 APPLIANCE PIPEWORK CONFIGURATION
The appliance ‘fl ow’ and ‘return’ connections can be
confi gured to suit the following:
1. Top outlet connection
2. Bottom outlet connection
3. Top (fl ow), bottom (return) connection
4. Top (return) bottom (fl ow) connection.
3A.11.1 FEED AND VENT PIPEWORK
The feed and vent pipe work from the boiler to the F&E
(Feed & Expansion) tank should be confi gured as shown
in fi gure 4A using a 22mm combined feed and vent pipe.
NOTE
●
The combined feed and vent pipe must rise continu-
ously and be unrestricted.
●
The diameter of the combined feed and vent pipe shall
be 22mm.
●
The minimum distance from the top of the boiler to the
bottom of the F&E tank shall be no less than 1-metre,
whilst the maximum distance shall be no greater than
30-metres.
The supply of water to the F&E tank should be taken
from the mains water supply via a suitable fl oat operated
valve, whilst the supply from the F&E tank to the boiler/
heating circuit (via the combined feed and vent pipe)
shall be unrestricted.
3A.11.2 ALTERNATIVE CLOSE-COUPLED
ARRANGEMENT
If necessary or if preferred, a close-coupled arrange-
ment for the feed and expansion pipe work can be used
as an alternative to a combined feed and vent pipe. The
confi guration of the close-coupled pipe work shall be as
shown in fi gure 4B.
NOTE
●
The distance between the cold feed pipe and the safety
vent pipe shall be no more than 150mm
●
The cold feed pipe must be inverted as shown in fi g.
4B
●
The safety vent pipe must be 22mm in diameter
●
The cold feed pipe must be 15mm diameter
●
The cold feed pipe and safety vent pipe must both rise
continuously and be unrestricted.
●
The minimum distance from the top of the boiler to the
bottom of the F&E tank shall be no less than 1-metre,
whilst the maximum distance shall be no greater than
30-metres.
●
The distance between the bottom of the F&E tank and
the highest point of the safety vent pipe must be no
less than 500mm.
The supply of water to the F&E tank should be taken from
the mains water supply via a suitable fl oat operated valve,
whilst the supply from the F&E tank to the boiler/heating
circuit (via the cold feed pipe) shall be unrestricted.
3A.11.3 REMOTE CONNECTION
It’s permissible to connect the feed and vent pipe work
remote from the appliance, providing it’s connected to
the primary heating pipe work as shown in fi gures 4C/4D.
NOTE
The instructions for a combined feed and vent installa-
tion (3A.11.1) or close-coupled arrangement (3A.11.2)
still apply when connecting the feed and vent pipe
work remote from the appliance.
3A.12 DECLARATION OF CONFORMITY
A Declaration of Conformity (as defi ned in I.S. 813) must
be provided on completion of the installation.
A copy of the declaration must be given to the responsible
person and also to the gas supplier if required.