11
221873B
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0
5
10
15
20
25
30
Circuit flow rate (l/min)
Remaining conveying capacity (m H
2
O)
0
10
20
30
40
50
60
∆
t (°C)
Dt at 100000 btu output
Dp (M H2O)
4.1 General Notes
The boiler is intended for use in a sealed system only.
4.2 Safety Valve
The safety valve is an integral part of the boiler.
It cannot be adjusted but has a manual test device.
4.3 Pressure Gauge
A pressure gauge is incorporated into the boiler to indicate the
system pressure.
The gauge has a cold fill set pointer.
4.4 Pump
The circulation pump is integral with the boiler.
The remaining circulating pressure head available from the
boiler is shown in diagram 4.1, Saunier Duval pump.
4.5 Expansion Vessel
The boiler has an integral expansion vessel with a capacity of
6 Litres. If the system water content exceeds the maximum
quoted in Table 1, Data, an additional vessel should be connected
into the system as close as possible to the central heating return
connection of the boiler, see diagram 4.2.
The charge pressure shall not be less that the static head at the
point of connection, that is, the height of the top point of the
system above the expansion vessel.
4.6 Flow Rate
A valve must be incorporated in the main flow or return of the
system, valve “A” shown in the flow diagram 4.2. This valve
must be lockable and positioned so that inadvertent closure or
unauthorised interference is not possible. The design differential
can be between 11
°
C (20
°
F) and 17
°
C (30
°
F), dependent upon
the system resistance and the available pump head.
Diagram 4.1
4 Heating System
4.7 Bypass
The bypass is an integral part of the boiler.
4.8 Filling Sealed Systems
An optional extra filling loop is available Part No. 457120
Provision for filling the system at a low level must be made.
Three methods of filling are shown in diagram 4.3.
There must be no permanent connection to the mains water
supply, even through a non-return valve.
NOTE: It is important that fittings used for connection to potable
water comply with the water undertakers requirements.
4.9 Corrosion Inhibitor
If an inhibitor is to be used in the system, contact the inhibitor
manufacturer so that they can recommend their most suitable
product.
When fitting the boiler into an existing system, special care
should be taken to drain the entire system, including radiators,
then thoroughly cleaning out before fitting the boiler whether or
not adding an inhibitor.
4.10 Draining
A draining tap must be provided at the lowest points of the
system, which will allow the entire system to be drained. An
additional draining tap MUST be fitted close to the boiler.
The flow and return isolation valves are provided with drain
points for boiler heat exchanger drainage.
7486
