Sealed Systems; Sealed System Requirements - Grant Vortex Pro Internal Combi Series Installation And Servicing Instructions

7

SEaLED SYStEMS

7.1 SEaLED SYStEM
REQUiREMEntS
All Grant Vortex Pro Combi boilers must be used as part of a
sealed system complying with the requirements of BS EN 12828,
BS EN 12831 and BS EN 14336.
The maximum temperature of the central heating water is 78°C.
The boiler is supplied factory fitted with the following items:
• 24 litre diaphragm expansion vessel complying with BS EN
13831*
• Pressure gauge
• Pressure relief (safety) valve
• Approved filling loop
* The Grant Combi XS 26 is supplied with a separate
24 litre expansion vessel (and mounting bracket) for
installation in a suitable position outside the boiler
casing. Refer to Section 4.9.
7.1.1 EXpanSiOn VESSEL
On all models except the Combi XS 26, the expansion vessel is
factory fitted on the front of the boiler, inside the casing.
It is connected to the boiler via a flexible hose to allow the vessel
to be removed from the boiler to access the boiler to access the
front cleaning door without disconnecting it. Take care to ensure
that the flexible hose is not twisted or kinked.
The Grant Combi XS 26 is supplied with a separate 24 litre
expansion vessel (and mounting bracket). This vessel should be
installed in a suitable location where it can be easily accessed for
servicing. Refer to Section 4.9 for further installation details.
! nOtE !
Ensure that the expansion vessel is of sufficient size for
the system volume.
Refer to BS 7074-1 or the Domestic heating Design Guide
to check the vessel size required.
If thermostatic radiator valves
are fitted, the system must
incorporate an adequate by-pass.
Boiler
Domestic
hot water
Expansion
vessel
Domestic
Heating flow
Stop valve
cold water
Water mains
figure 7-1: Sealed system
Section 7: Sealed Systems
7.1.2
The pressure gauge is factory fitted in the boiler control panel. It
has an operating range of 0 to 4 bar. Refer to Section 1.4.
7.1.3
The safety valve is factory fitted to the flow pipework on the top of
the boiler.
A discharge pipe should be connected to the outlet of the safety
valve. This discharge pipe must terminate in a position that will
allow the discharge to be seen, but cannot cause injury to persons
or damage to property. Refer to Section 5.1 for further details.
7.1.4
In order to fill or top up the heating system, a factory fitted
filling loop is located at the front of the boiler, to the right of the
expansion vessel.
Refer to Section 4.10 for details on how to fill and vent the system.
7.1.5
The maximum 'setpoint' temperature for the central heating water
is 78°C. Refer to Section 1.1.
An automatic air vent should be fitted in the flow and return pipes
of the highest point of the system.
If thermostatic radiator valves are fitted to all radiators, a system
by-pass must be fitted. The by-pass must be an automatic type.
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.
One or more drain taps (to BS 2879) must be used to allow the
system to be completely drained.
Static head of system
Heating
return
By-pass if required
(automatic type)
pRESSURE GaUGE
SafEtY VaLVE
fiLLinG LOOp
hEatinG SYStEM
page 21