Bosch Worcester Greenstar Danesmoor External Regular ErP+ 12/18 Installation, Commissioning And Servicing Instruction Manual page 13

Open vent primary system (regular only)
• The open vent pipe [F] and feed and expansion pipe [H must rise
continuously from the appliance.
• The feed and expansion cistern [E] must be positioned to provide a
static head [S] of at least 1 metre above the highest point in the
heating system to the water level in the feed and expansion cistern
[E].
• Ensure adequate space is left in the expansion cistern for expansion
of the system water.
• No valve shall be fitted in the open vent pipe (F) or the feed and
expansion pipe [H].
• The open vent pipe [F] must be at least 22mmØ.
Fig. 8 Regular appliance open vent layout
[A] Regular appliance
[A1] System appliance
[B] Expansion vessel*
[C] Automatic bypass valve
[D] Drain cock
[E] Feed and expansion cistern
[F] Open vent 22mmØ min.
[G] Pressure gauge*
[H] Feed and expansion 15mmØ min.
[J] Circulating pump*
[K] Zone valves
[K1] Three port valve
[L] Lockshield valve
[M] Hot water cylinder
[N] Automatic air vent
[P] Pressure relief valve*
[P1] Pressure relief discharge
[R] Radiators
[T] Thermostatic radiator valve TRV
[U] To filling system
[NOTE] * Components included internally on the system boiler
Greenstar Danesmoor External ErP+ and External System
Fully pumped sealed primary system:
• A pressure relief valve [P], spring loaded safety valve set to operate
at 3bar, must be fitted to the heating flow pipe as close as possible to
the boiler or onto one of the boiler top 1" BSP outlets.
• An expansion vessel [B] must be fitted to the heating return pipe as
close as possible to the boiler and pressurised for the system volume
according to the instructions supplied with the vessel.
• A pressure gauge [G], 3 bar minimum, must be fitted to the heating
flow pipe or one of the boiler 1" BSP outlets.
• An automatic air vent [N] must be fitted.
Fig. 9
6720808218-07.1Wo
Fig. 10 System appliance system layout
Sealed system considerations
Total system volume
(litres)
ErP+ 6720821725 (2018/04)
K1
Regular appliance system layout
A1
P1
K1
The charge pressure of the built-in 12 litre expansion
vessel is 0.5 bar as dispatched, which is equivalent to a
static head of five metres.
Initial system
pressure (bar)
180 0.5
107 1.0
138 1.0
If an extra expansion vessel is fitted to the central
heating return, adjust this to the same pressure as the
appliance internal expansion vessel, refer to separate
instructions supplied with the extra expansion vessel.
Pre-Installation
6720808218-08.1Wo
6720808218-109.1Wo
Initial charge
pressure (bar)
0.5
0.5
1.0
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