Water Systems & Pipework - Worcester GREENSTAR 25Si Instruction Manual

SYSTEM FILL
TYPICAL SEALED SYSTEM
A - Appliance expansion vessel -
central heating
B - Extra expansion vessel -
central heating return
C - Drain cock
P - Pressure relief discharge
R - Radiators
A
B
P
INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR 25Si/30Si
8 716 115 165a (06/2008)
R
R
C
WATER SYSTEMS & PIPEWORK
R
R
C
PLASTIC PIPEWORK:
• Any plastic pipework must have a polymeric
barrier with 600mm (minimum) length of
copper pipe connected to the boiler.
• Plastic pipework used for underfloor heating
must be correctly controlled with a
thermostatic blending valve limiting the
temperature of the circuits to approx. 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 lockshield 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.
NOTE: 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.
IMPORTANT: ARTIFICIALLY SOFTENED
WATER MUST NOT BE USED TO FILL THE
CENTRAL HEATING SYSTEM
SEALED PRIMARY SYSTEM:
• The CH sealed system must be filled using a
WRAS approved filling loop or comply with
the diagram opposite 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 (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.
• Do not use galvanised pipes or radiators.
WATER SYSTEMS & PIPEWORK
11