Sealed Systems; Sealed System Requirements - Grant Vortex 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 75°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
7.1.1 EXPANSION VESSEL
On all models 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 front cleaning door
without disconnecting it. Take care to ensure that the flexible hose
is not twisted or kinked.
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.
Domestic
hot water
Domestic
cold water
Figure 7-1: Sealed system
Page 20
Boiler
Expansion
vessel
Stop valve
Water mains
7.1.2 PRESSURE GAUGE
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 PRESSURE RELIEF (SAFETY) VALVE
The pressure relief (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 pressure
relief (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 Figure 5-1 for
the position of the PRV on all models.
7.1.4 FILLING LOOP
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 7.2 for details on how to fill and vent the system.
7.1.5 HEATING SYSTEM
The maximum 'setpoint' temperature for the central heating water
is 75°C. Refer to Section 1.1.
An 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)
Section 7: Sealed Systems