Instruction manual

be reset by turning a screw (D Fig. 22) anti-clockwise to
open the by-pass using the chart below for guidance.
If used on a system with thermostatic radiator valves,
the flow rate with thermostatic valves closed should be
adjusted to at least 100 Vhr.
The chart below indicates the residual head of the pump
available for the system.
Expansion Vessels
Boiler
The expansion vessel is pre-charged to 0.7 bar
(lOlb/it-?). The vessel is suitable for systems up to 145
litres capacity. For systems of greater capacity an
additional expansion vessel will be required. Refer to
the chart below and BS 7074 pt. 1 or BS 5449.
Cylinder
The domestic hot water expansion vessel is pre-charged
to 3 bar (45.51b/in2).
The vessel is suitable for the 55 litre of water in the
cylinder.
Filling Point
Provision must be made to be able to charge the system
on commissioning and to make up any subsequent
pressure loss. The method of connection must utilise
approved equipment and must comply with the water
regulations. A filling loop can be so installed as to be
hidden beneath the boiler.
Fig. 22
Head and flow rate available
m H,O <- Minimum flow rate
I
0 100 200 300 400
500 600 700 800 90010001100
Fig. 23
l/h
Pressure
System Capacity Chart
zo
199
13
I,7
1,6
13
1,4
1,3
12
l,l
1s
‘J,Q
03
0,7
20 40 60 80 100
120 140 160 180 200 220 240 260
Litres
Fig. 24