IDEAL VANGUARD L 170 Installation And Servicing page 10

6 oPEN VENTED SySTEm - minimum static head requirements
The Vanguard L boiler has a minimum static head requirement
of 2.5 metres (8 feet approx.) depending on the particular
characteristics of the system design (see diagram).
The information provided is based on the following
assumptions:
1. An open vent/safety pipe connection is made from the
Safety Valve and Expansion connection point on the boiler
body.
2. A cold feed/expansion pipe connection is made to the
system return pipe within 0.75m of the boiler return
connection.
3. The maximum flow rate through the boiler is based on a
temperature difference of 11ºC (20ºF) at full boiler output
with the circulating pump positioned in the flow of the
system.
Cold feed/
expansion pipe
10
GENERAL
Shunt pump
(if required)
Boiler
4. The boiler is at the highest point of the system. Systems
designed to rise above the flow connections will, of course,
automatically require a minimum static head higher than
shown.
5. The position of the open vent/safety pipe above the expansion
cistern water level is given as a guide only. The final position
will depend upon particular characteristics of the system.
Pumping over of water into the expansion cistern should be
avoided.
6. Both open vent/safety pipe and cold feed/expansion pipes
must be of adequate diameter to suit the output of the boiler
(see table below).
Boiler output kW
151 to 300
301 to 600
above 600
750 mm
Expansion
cistern
*
2.5 m
To pump
*
Note: Height MUST
be increased if necessary
to comply with the min.
head required by the
pump manufacturer
open Vent (mm) cold feed (mm)
38
50
63
Open vent
safety pipe
Mains water
supply
Vanguard L -
Installation & Servicing
32
38
50