Water Systems & Pipework - Worcester GREENSTAR HEATSLAVE 12/18 Instruction Manual

TYPICAL SEALED SYSTEM
A
E
B
U
P
A - Appliance expansion vessel
B - Extra expansion vessel
C - Automatic bypass valve
D - Drain cock
E - Appliance
12
WATER SYSTEMS & PIPEWORK
T
L
C
D
L - Lockshield valve
P - Pressure relief discharge
R - Radiators
T - TRV
INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR HEATSLAVE 12/18-18/25-25/32
R R
T
L L
R R
T
L L
D
WATER SYSTEMS & PIPEWORK
IMPORTANT: The boiler should not be
allowed to operate with a return
temperature of less than 4 0°C when
the system is up to operating temperature.
PRIMARY SYSTEM PLASTIC PIPEWORK:
• Any plastic pipework used for the CH system
must have a polymeric barrier, complying with
BS 7921 and installed to BS 5955 with
1000mm (minimum) length of copper or steel
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
with 1000mm (minimum) length of copper or
steel pipe connected to the boiler, and a 20k
differential must be maintained at the
appliance.
PRIMARY SYSTEM/CONNECTIONS/VALVES:
• Do not use galvanised pipes or radiators.
• All system connections, taps and mixing
valves must be capable of sustaining a
pressure of 3 bar.
• Radiator valves should conform to
BS 2767:10.
• All other valves should conform to BS 1010.
• On new installations TRVs must be used on
all radiators except the radiator where the
room thermostat is sited, this must be fitted
with lockshield valves and left open. All
installations should have TRVs fitted to
radiators within the sleeping accommodation.
• An automatic bypass valve must be connected
between the heating flow and return pipes
where TRVs are used on radiators. This must
be fitted to give at least a 3m circuit when
activated.
• Drain cocks are required at all the lowest
points on the system.
• Air vents are required at all high points on the
system.
SEALED PRIMARY SYSTEM:
• Where the system volume is more than 180
litres at 0.5 bar 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 (A)
built into the appliance.
IMPORTANT:
The Greenstar Heatslave boiler is for use
with sealed central heating systems only.
6 720 802 432 issue A 04/2012