6.0 System Details
14
6.6
System Filling and Pressurising
(Fig. 10)
1. A filling point connection on the central heating return
pipework must be provided to facilitate initial filling and
pressurising and also any subsequent water loss
replacement/refilling.
2. The filling method adopted must be in accordance
with the Water Supply (Water Fittings) regulations and
the Water Bylaws (Scotland).
3. Your attention is drawn to, for GB: Guidance G24.2
and recommendation R24.2 of the Water Regulations
Guide. for IE: the current edition of I.S. 813 “Domestic
Gas Installations”.
4. The sealed primary circuits may be filled or
replenished by means of a temporary connection
between the primary circuit and a supply pipe provided
the arrangement in accordance with Diagram R24.2a of
the Water Regulations Guide.
5. The temporary hose must be completely removed at
both ends after use.
6.7
Expansion Vessel
(Fig. 11)
1. The appliance expansion vessel is pre-charged to 1
bar (10 lb/in
2
). Therefore, the minimum cold fill pressure
is 1 bar. The vessel is suitable for correct operation for
system capacities up to 125 litres (27.5 gal). For greater
system capacities an additional expansion vessel must be
fitted - refer to BS 7074 Pt 1.
6.8
Pressure Relief Valve
(Fig. 11)
1. The pressure relief valve is set at 3 bar, therefore all
pipework, fittings, etc. should be suitable for pressures in
excess of 3 bar.
2. The pressure relief discharge pipe should be not less
than 15mm dia, run continuously downward, and
discharge outside the building, preferably over a drain. It
should be routed in such a manner that no hazard
occurs to occupants or causes damage to wiring or
electrical components. The end of the pipe should
terminate facing down and towards the wall.
3. The discharge must not be above a window, entrance
or other public access. Consideration must be given to
the possibility that boiling water/steam could discharge
from the pipe.
Fig. 10
Stop
Valve
Double
Check
Valve
Cold
Mains
CH
Return
Temporary
Hose
Stop
Valve
Pressure Relief
Valve
Expansion Vessel
removed for clarity
Fig. 11
Expansion Vessel
Summary of Contents for System 100 HE Plus
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