Alpha CD13R Installation And Servicing Instructions page 9

3.7 CENTRAL HEATING SYSTEM - Fig. 5 and 5a
The boiler is designed for use in an open or (if the alpha sealed system kit is used) sealed central heating system in accordance
with the requirements of BS 5449 and BS 6798.
3.8 FILLING THE OPEN VENTED CENTRAL HEATING SYSTEM
A minimum head of 1 m is required between the boiler/pump and the feed and expansion tank.
The boiler must be supplied from an unrestricted water supply taken from a feed and expansion cistern situated at a maximum
height of 27 m above the boiler.
The cold feed must be 15 mm minimum size. The vent should be 22 mm in size, rise continuously and be unrestricted.
It is important that the relative positions of the pump, cold feed and open vents are as shown in Fig. 5.
The domestict hot water cylinder must be of the fully indirect coil type.
Vent (22mm min)
150mm max
Cold feed
(15mm min)
Boiler
Pump
by-pass valve
Fig. 5 - Open system with Y-Plan
Manual air vents
Boiler
Pump Automatic
by-pass valve
Fig. 5a - Sealed system with Y-Plan
Alpha CD13R, 18R, 24R - General Boiler Information
450mm min height
Feed and
expansion tank
1000mm min height
Mid position
3-port valve
Automatic
Balancing
valve
Make-up
vessel
Double
check valve
Pressure
gauge
Discharge
Expansion
vessel
Mid position
3-port valve
Balancing
valve
DHW storage
cylinder
Above highest
point of system
Filling point
pipe
DHW storage
cylinder
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