Halstead Ace High, Installation And Servicing Instructions, Page: 12 / 40

10
EXPANSION VESSEL
The table below shows the maximum system volume that the
integral expansion vessel can sustain under different charge
pressure conditions (pre-charged to 0.75 bar). If the system
volume exceeds that shown, an additional expansion vessel must
be fitted and connected to the heating system primary return pipe
as close as possible to the appliance. If an extra vessel is
required, ensure that the total capacity of both vessels is
adequate. Further details are available in the current issues of
BS5449 and BS6798.
NOTE : If the pressure gauge indicates 2.65 bar or greater when the
appliance is at maximum temperature with all radiators in circulation an
extra expansion vessel is required.
PRESSURE GAUGE A pressure gauge is situated on the
appliance control panel.
PRESSURE RELIEF VALVE A pressure relief valve set at 3 bar
(43.5 psi) is supplied with the appliance.
a) Check that the mains water pressure is sufficient (as stated in
2.4 “General Specification”) to produce the required DHW
flow rate, but does not exceed the maximum DHW pressure
(10 bar). If necessary, a pressure reducing valve must be
fitted to the mains supply before the DHW inlet connection.
b) The final 600mm (24in) of the mains supply pipe to the boiler
must be copper.
c) Avoid long DHW pipe runs and several hot water draw off
points
d) Insulate the Hot water pipes if accessible to minimise the heat
losses within the pipes to keep the water hot longer.
e) A domestic hot water regulator is fitted within the group set to
control the maximum water flow rate. This may be removed to
obtain higher flow rates. Higher flow rates will not damage
the appliance but may reduce the water temperature below an
acceptable level.
f) If the appliance is installed in an area where the temporary
hardness of the water supply is high, say over 150ppm, the
fitting of an in-line scale inhibitor may be an advantage.
Consult the Local Water Supplier if in doubt.
g) For specific information relating to fittings (eg. Showers,
Washing Machines etc) suitable for connection in the DHW
circuit, consult the Local Water Supplier. However the
following information is given for guidance:
DOMESTIC HOT/COLD WATER SUPPLY TAPS AND
MIXING TAPS. All equipment designed for use at mains
water pressure is suitable.
SHOWERS & BIDETS . Any mains pressure shower or bidet
complying with the Local Water Undertaking bylaws is suitable.
h) Consider IRN 116 and Byelaw 90 + 91. Ensure that
necessary action have been carried out to account for thermal
expansion of water. If thermal expansion is not provided then
high water pressure may result in damaging to fittings and
devices.
a) Wiring external to the appliance must be in accordance with
the current l.E.E. Wiring Regulations (BS 7671) for electrical
installation and any local regulations which apply.
b) The mains cable must be at least 0.75mm 2 (24/0.2mm)
PVC Insulated to BS6500 table 16.
c) THIS APPLIANCE MUST BE EARTHED. (Failure to provide
a satisfactory Earth connection will result in appliance
malfunction)
d) The method of connection to the mains supply must facilitate
complete electrical isolation of the appliance. Either a 3A
Fused three pin plug and unswitched shuttered socket outlet,
both complying with BS1363, or a 3A fused double pole
switch having a 3mm contact separation in both poles and
serving only the boiler (and its external controls) may be used.
The appliance may be used with any Certificated mains voltage
room thermostat and/or single channel programmer as described
in section 4.8.
3.7 DOMESTIC HOT WATER SYSTEM
3.8 ELECTRICITY SUPPLY
3.9 EXTERNAL CONTROLS
EXPANSION VESSEL REQUIREMENTS
Vessel charge and initial
system pressure
Total water content of system
using 8ltr. (1.54gal) capacity expansion
vessel supplied with appliance
For systems having a larger
capacity multiply the total system capacity
in litres (gallons) by the factor to obtain the
total minimum expansion vessel capacity required litres (gallons)
bar 0.5 0.75 1.0 1.5
psi 7.3 11 14.5 21.8
96ltr 84ltr 73ltr 50ltr
21gal 18gal 16gal 11gal
0.0833 0.093 0.109 0.156
14
ALTERNATIVE METHODS OF FILLING A SEALED SYSTEM
•
MAINS WATER
SUPPLY
•
•
•
DOUBLE
CHECK
VALVE
ASSEMBLY
•
STOP
VALVE
•
STOP
VALVE
•
HEATING SYSTEM
RETURN
•
CISTERN &
OVERFLOW
•
MAINS
WATER SUPPLY
•
PRESSURE PUMP
& REDUCING VALVE
IF REQUIRED
•
STOP
VALVE
•
HEATING
SYSTEM
RETURN
FLEXIBLE HOSE UNION
TEMPORARY CONNECTION
To be removed immediately after filling
RECOMMENDED AND APPROVED METHOD FOR
FILLING A CLOSED CIRCUIT IN A HOUSE.
(R24-2a WATER REGULATIONS GUIDE)