Worcester Greenstar Heatslave II ErP 12/18 Installation, Commissioning And Servicing Instruction Manual page 13

expansion vessel (B) must be fitted as close as possible to the
appliance in the central heating return.
• Pressurise the extra expansion vessel (B) to the same figure as the
expansion vessel (A) built into the appliance.
A
E
B
U
P
C
Fig. 8 Regular boiler, open vent system layout
[A] Expansion vessel*
[B] Extra expansion vessel
[C] Automatic bypass valve
[D] Drain cock
[E] Appliance
[L] Lockshield valve
[R] Radiators
[T] Thermostatic radiator valve TRV
[U] To filling system
Filling primary sealed systems
Filling the system
▶ The system must not be filled with artificially
softened water.
• Where the system volume is more than 180 litres at 0.5 bar or
exceeds 2.65 bar at maximum heating temperature an extra
expansion vessel [B] must be fitted as close as possible to the
appliance in the central heating return.
• Pressurise the extra expansion vessel [B] to the same figure as the
expansion vessel built into the appliance.
• Filling the system must comply with the method shown in the figure
below.
• The filling point must be at low level and must never be a permanent
connection to the mains water supply.
• Filling loops must be WRAS approved.
SYSTEM FILL
Heating
return
Hose union
SV
Temporary hose
CV = Check Valve
SV = Stop Valve
Fig. 9
Greenstar Heatslave II ErP - 6 720 813 344 (2014/09)
R R
T
T
L
L
R R
L T
L
L
D
D
6720805209-82.1Wo
Mains
supply
CV CV
SV
Test point
AA = Auto Air vent
CV = Check Valve
Mini expansion
vessel
(0.75ltr capacity)
3 bar pressure
Incoming
reducing
mains
valve
stop valve
MCW
Check valve/
non return valve
Balanced cold water
supply to property
Fig. 10
Showers/Bidets:
• If a shower head can be immersed in water or comes closer than
25mm from the top edge of a bath or shower tray spill over level then
an anti-siphon device must be fitted to the shower hose.
Only thermostatically controlled showers are suitable for use with
this appliance.
• Bidets with direct hot & cold mains water can be used (with the
approval of the local water authority) and must be the over rim
flushing type with shrouded outlets to prevent the fitting of hand held
sprays.
Domestic hot water:
Plastic pipework
• Any plastic pipework used for the DHW system must have a
polymeric barrier, complying with BS 7921 and installed to BS 5955
with 1000mm (minimum) length of copper or stainless steel pipe
connected to the boiler.
• Before installing plastic pipework, the pipe manufacturer's literature
should be consulted.
• To prevent the temperature & pressure exceeding the limits advised
by the pipe manufacturer, a pressure reducing valve must be used to
prevent the incoming water pressure exceeding 3 bar (maximum).
Also a mini expansion vessel must be fitted to absorb the expanding
water and a blending valve set to 60°C must be fitted before the DHW
plastic pipework.
• When selecting plastic pipework for use with domestic water supply,
it should be ensured that it is compliant with all current local &
national legislation & regulations, including building regulations part
G, BS 7291 - 1,2 & 3: 2006, BS 8000 - 15-15: 1990 and
information.
General:
• Taps and mixing valves must be capable of sustaining a pressure up
to 10 bar in accordance with the Water Regulations as they will be
operating at mains water pressure.
• Hot water temperature and flow rate are affected by the size and
insulation of pipework making up the distribution system and are
controlled by the hot water tap and the water main inlet pressure. A
mixing valve can be fitted if a more permanent setting is required.
• If using more than one outlet at once causes water flow starvation, fit
flow balancing valves or Ball-O-Fix valves to the appropriate outlets.
Pre-Installation
Hot water supply
to property
Greenstar Heatslave II
oil fired
combination boiler
Blending valve
set to 60°C
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