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6.0 SYSTEM DETAILS
Publication No. 5111811
6.5 System Filling and Pressurising
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. There are connection points on the mains cold
water inlet and central heating return isolating taps to
which the optional filling loop kit (Part No. 248221)
can be assembled.
3. The filling method adopted must be in accordance
with all relevant water supply regulations and use
approved equipment.
4. 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”.
5. The sealed primary circuits may be filled or
replenished by means of a temporary connection
between the circuit and a supply pipe, provided a
‘Listed’ double check valve or some other no less
effective backflow prevention device is permanently
connected at the inlet to the circuit and the
temporary connection is removed after use.
6.6 Expansion Vessel
(Central Heating only)
1. The appliance expansion vessel is pre-charged to
0.5 bar. Therefore, the minimum cold fill pressure is
0.5 bar. The vessel is suitable for correct operation
for system capacities up to 125 litres. For greater
system capacities an additional expansion vessel
must be fitted. For GB refer to BS 7074 Pt 1. For IE,
the current edition of I.S. 813 “Domestic Gas
Installations”.
6.7 Pressure Relief Valve (Fig. 9)
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 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. 8
Fig. 9
Stop
Valve
Double
Check
Valve
DHW
Mains
Inlet
CH
Return
Temporary
Hose
Pressure Relief Valve
Discharge Pipe
Stop
Valve