Grant VORTEX Pro Combi Series User Manual

Sealed Systems
21
7 Sealed Systems
7.1 System Models
All Grant Vortex Pro Combi e boilers are
supplied for use as part of a sealed
system complying with the requirements
of BS 5449.
The maximum temperature of the
central heating water is 78° C.
• Pressure relief safety valve
complying with BS 6759 and set to
operate at 2.5 bar. The discharge
pipe must be routed clear of the
boiler to a drain, in such a manner
that it can be seen, but cannot
cause injury to persons or property.
• Automatic air vent, fitted to the top
of the boiler, ensures the boiler is
vented.
• Filling loop. This must be isolated
and disconnected after filling the
system.
Refer to Section 4.5 for further details of
the expansion vessel.
The expansion vessel charge pressure
should always be slightly greater than
the maximum static head of the system,
in bar, at the level of the vessel (1 bar =
10.2 metres of water). See Figure 7-1.
The boilers are supplied with the
following items factory fitted:
• A diaphragm expansion vessel
complying with BS 4814, pre-
charged at 1.0 bar, size as follows:
10 litre for Vortex Pro Combi 21e
12 litre for Vortex Pro Combi 26e
14 litre for Vortex Pro Combi 36e.
System pressure gauge, with an
operating range of 1 to 4 bar.
The system fill pressure (cold) should be
0.2-0.3 bar greater than the vessel
charge pressure - giving typical system
fill pressures of approx 0.5 bar for a
bungalow and 1.0 bar for a two-storey
house. Refer to the Domestic Heating
Design Guide for more information if
required.
If thermostatic radiator valves are fitted
to all radiators, a system by-pass must
be fitted. The bypass must be an
automatic type.
Provision should be made to replace
water lost from the system. This may be
done manually (where allowed by the
local Water Undertaking) using the filling
loop arrangement supplied with the
boiler.
Filling of the system must be carried out
in a manner approved by the local
Water Undertaking.
Where allowed, the system may be filled
via the filling loop supplied (the loop
arrangement includes a double check
valve assembly).
All fittings used in the system must be
able to withstand pressures up to 3 bar.
Radiator valves must comply with the
requirements of BS 2767(10):1972.
One or more drain taps (to BS 2879)
must be used to allow the system to be
completely drained.
The expansion vessel is connected via a
flexible hose to allow it to be moved to
gain access to the baffle cleaning cover.
When replacing the vessel, care should
be taken to ensure that the flexible
connecting hose is not twisted.
Figure 7-1: Sealed system
Static head of system
Heating flow
Heating
return
By-pass if required
(automatic type)
350mm
Boiler
Expansion
vessel
If thermostatic radiator valves
are fitted, the system must
incorporate an adequate by-pass.
When designing a system, the pump
head, expansion vessel size, and
radiator mean temperature are
amongst the factors that must be
considered. See Section 4.5.
!
NOTE
Ensure that the expansion vessel is
of sufficient size for the system
volume (including the volume of the
boiler). If necessary a second vessel
may need to be fitted to the system.
Refer to Section 2.1 for system
volume. To determine total vessel
volume required refer to
BS7074:1:1989 or the Domestic
Heating Design Guide.
!
NOTE
Stop valve
Water mains
Domestic
hot water
Domestic
cold water

Grant VORTEX Pro Combi Series Specifications

General

Brand	Grant
Model	VORTEX Pro Combi Series
Category	Boiler
Language	English