Water Systems & Pipework - Bosch Worcester GREENSTAR CDi Series Instruction Manual

TYPICAL SEALED SYSTEM
A-
B-
C-
p-
R-
Appliance expansion vessel
- central heating
Extra expansion vessel
- central heating return
Drain cock
Pressure relief discharge
Radiators
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6 720 611 927-02.10
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INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER BOSCH GREENSTAR 25CDV30CDV37CDci42CD•
6 720 613 700a (2006/11)
Bosch Group
WATER SYSTEMS & PIPEWORK
PLASTIC PIPEWORK:
• Any plastic pipework must have a polymeric
barrier with 600 mm (minimum) length of
copper or steel pipe connected to the boiler.
Plastic pipework used for underfloor heating
must be correctly controlled with a thermo-
static blending valve limiting the temperature
of the circuits to approx. 50°C.
The pipework from the boiler to the blending
valve must be in copper or steel (protected
from corrosion).
CONNECTIONS/VALVES:
• All system connections, taps and mixing
valves must be capable of sustaining a pres-
sure up to 3 bar.
Radiator valves should conform to
BS2767:10.
• All other valves should conform to BS 1010.
On new installations, or extensions to exist-
ing systems where a radiator previously did
not exist, each radiator should be fitted with
a TRV, except the one fitted in the same
room/area as the room thermostat.
On boiler only replacement jobs, it is recom-
mended, (but not mandatory,) to fit a TRV on
each radiator. It is, however, a requirement,
for energy conservation purposes, to recom-
mend to the customer that a TRV is fitted to
each radiator.
• An automatic bypass may be required,
(downstream of the pump), in order to main-
tain the minimum flow-rate through the appli-
ance.
• A drain cock is required at the lowest point
on the system.
• An air vent is required at the highest point
on the system.
SHOWERS/BIDETS
If a shower head can be immersed in water
or comes closer than 25 mm 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.
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 pre-
vent the fitting of hand held sprays.
SEALED PRIMARY SYSTEM:
The CH sealed system must be filled using
the built-in filling link (see page 23).
Where the system volume is more than
100 litres or exceeds 2.65 bar at maximum
heating temperature an extra expansion ves-
sel (B) must be fitted as close as possible
to the appliance in the central heating
return.
Pressurize 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