13
4.7 CENTRAL HEATING SYSTEM - Figs. 4.5 and 4.6
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. The external pump must be able to achieve a minimum flow rate of 900 l/h on
open systems or 515 l/h on sealed systems.
Alpha E-Tec 15, 20, 25R - General Boiler Information
Fig. 4.5 - Open system with Y-Plan
Fig. 4.6 - Sealed system with Y-Plan
4.8 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. 4.5.
The domestict hot water cylinder must be of the fully indirect coil type.
Boiler
150mm max
1000mm min height
Feed and
expansion tank
Vent (22mm min)
Cold feed
(15mm min)
Pump
DHW storage
cylinder
Mid position 3-port valve
or Alpha diverter valve
with cylinder sensor
Automatic
by-pass valve
Balancing
valve
450mm min height
Magnetic type filter
recommended
Pump
Boiler
DHW storage
cylinder
Automatic
by-pass valve
Balancing
valve
Manual air vents
Pressure gauge
Expansion vessel
Discharge
pipe
Filling point
Mid position 3-port valve or
Alpha diverter valve
with cylinder sensor
Magnetic type filter
recommended
Expansion
valve
To Next Page
Loading...
