Water Systems And Pipe Work - Worcester GREENSTAR 24i Junior Installation Instructions Manual

3.3

WATER SYSTEMS AND PIPE WORK

PLASTIC PIPE WORK:
• Any plastic pipe work must have a polymeric barrier
with 600mm (minimum) length of copper pipe
connected to the boiler.
• Plastic pipe work used for underfloor heating must be
correctly controlled with a thermostatic blending
valve limiting the temperature of the circuits to
approximately 50 °C.
PRIMARY SYSTEMS CONNECTIONS/VALVES:
• All system connections, taps and mixing valves must
be capable of sustaining a pressure up to 3 bar.
• Radiator valves should conform to BS2767:10.
• All other valves should conform to BS1010.
• Thermostatic radiator valves (TRV's) must be used on
all radiators within the sleeping accommodation but
not the radiator where the room thermostat is sited.
This must be fitted with lock-shield valves and left
open.
• A drain cock is required at the lowest point in the
system.
• An air vent is required at all the high points in the
system.
The boiler is equipped with an automatic
internal by-pass.
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-syphon device
must be fitted to the shower hose.
• Bidets with direct hot and 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.
6 720 644 741a (2010/10)
SEALED PRIMARY SYSTEM:
NOTICE: ARTIFICALLY SOFTENED WATER
MUST NOT BE USED TO FILL THE CENTRAL
HEATING SYSTEM
• The CH sealed system must be filled using a WRAS
approved filling loop or comply with figure 4 for
system fill.
• Where the system volume is more than 100 litres or
exceeds 2.65 bar at maximum heating temperature,
an extra expansion vessel (2) must be fitted as close
as possible to the appliance in the central heating
return.
• Pressurise the extra expansion vessel (2) to the same
figure as the expansion vessel built into the appliance.
• Do not use galvanised pipes or radiators.
SYSTEM FILL
Heating
return
Hose union
SV
Temporary hose
CV = Check Valve
SV = Stop Valve
Fig. 4 System fill
TYPICAL SEALED SYSTEM
1
2
3
4
Fig. 5 Sealed system
1 Appliance expansion vessel - CH
2 Extra expansion vessel - CH return
3 Pressure relief discharge
4 Drain cock
5 Radiators
Tab. 9 Key to fig. 5
PRE-INSTALLATION
Mains
supply
CV CV
SV
Test point
6720643895-05.1Wo
5 5
5 5
4
6720643895-06.1Wo
13