17
fig. 14
GW 406/0
4.4 Pipework connections
(fig. 14)
Figure 14 shows the central heating,
domestic hot water, mains cold water
and pressure relief valve connections.
4.4.1 Central heating flow
and return
Before connecting the heating circuit
to the connection group, all pipework
and radiators must be thoroughly
flushed to remove any installation
debris. Connect the flow and return
pipes to the central heating service
valves (8) and (9) on the connection
group using compression adaptors.
4.4.2 Cold mains water inlet
and hot water outlet
Flush out all foreign matter from the
mains supply pipe before connecting
to the boiler.
Connect the mains water supply (3)
and hot water outlet pipes (4) to the
15 mm compression connections pro-
vided.
Note: The boiler has a maximum
domestic water working pressure of
10 Bar. If the cold mains supply pres-
sure exceeds 10 Bar, a pressure red-
ucing valve must be fitted to the cold
water inlet.
4.4.3 Pressure relief valve
discharge
The connection group contains the
pressure relief valve required for a
sealed system (5). Connect a dis-
charge pipe not less than 15 mm dia-
meter to the Rc
3
/
4
outlet of this valve
using a compression adaptor.
This discharge pipework should be as
short as possible and installed with a
continuous fall away from the boiler.
The pipe should terminate in a posi-
tion which ensures that any discharge
of water or steam from the valve can-
not create a hazard to persons in or
about the premises, or damage to any
electrical components or external
wiring, and the point of discharge
should be clearly visible. The dis-
charge must not terminate above a
window, an entrance or any type of
public access. The installer must con-
sider that the pipe could discharge
boiling water.
Key:
1 CH Flow pipe
2 CH Return pipe
3 Cold Mains water supply
4 DHW outlet
5 CH Pressure relief valve (PRV)
6 PRV discharge pipe
7 Cold Mains water service valve
8 CH Flow service valve
9 CH Return service valve
