801
12
Built-in Central Heating Water Circulating Pump
The pump head available for circulating the water is given in fig. 8.
N.B. - The pump is factory set at position 3. The pump is a Grundfos type 15-50 UPS series.
Grunfos Pump performance graph
Note - Minimum flow through boiler heat exchanger at any time should not fall below 6 litres per minute.
If required an additional expansion vessel may be fitted to the central heating return inlet.
If the total volume of water in the system exceeds 40 litres an additional expansion vessel must
be fitted to the central heating return inlet.
Pump performance curve Grundfos UPS 15-50
1 2 3 Speed settings
A Boiler pressure drop
B Max. available pump head C.H.
Fig. 8
SIZING OF ADDITIONAL EXPANSION VESSELS:
Deduct from the value given in the table the 7 litre
vessel supplied.
Note
1. Fill C.H. installation to min. 1.5 bar.
2. Select by preference the expansion vessel for
increased system pressure of 2.0 bar
3. Expansion vessel must be fitted to Central Heating
Return Inlet
4. The standard 7 litres expansion vessel is charged
to 1 bar
Fig. 9
SAFETY VALVE
SETTING (bar)
VESSEL CHARGE
PRESSURE (bar)
INITIAL SYSTEM
PRESSURE (bar)
TOTAL WATER
CONTENT of SYSTEM
3.0
0.5
1.0
1.5
1.0
1.5
2.0
1.5
2.0
2.0
EXPANSION VESSEL VOLUME (litres)
LITRES
25
3.5
6.5
13.7
4.7
10.3
8.3
50
7.0
12.9
27.5
9.5
20.6
16.5
75
10.5
19.4
41.3
14.2
30.9
24.8
100
14.0
25.9
55.1
19.0
41.2
33.1
125
17.5
32.4
68.9
23.7
51.5
41.3
150
21.0
38.8
82.6
28.5
61.8
49.6
175
24.5
45.3
96.4
33.2
72.1
57.9
200
28.0
51.8
110.2
38.0
82.4
66.2
0.140
0.259
0.551
0.190
0.412
0.33
For syst. volumes other than
those given above, mult. the syst.
volume by the factor across
