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Installation and maintenance instructions ecoTEC plus 937 0020031552_06
4.8.5 Heating circuit expansion vessel
The boiler of the ecoTEC series are equipped with a
10 litre expansion vessel which is suitable for a sealed
heating
system with a maximum water volume of 100 litres.
If the nominal capacity of the boiler expansion vessel is
not adequate for the heating system (e.g. when modern-
ising old open systems) an additional expansion vessel
can be fitted outside the boiler. The pressure gauge
must be fitted in the return pipe, in accordance with
BS 5449: Part 1, as close as possible to the boiler.
In Table 4.5 you will find an overview of the required
size of an additional expansion vessel.
Vessel volume
(in l)
Initial system pressure (in bar)
1.0
1.5
Setting of the excess pressure valve (in
bar)
3.0
Total water volume of the system (in l)
25
2.7
3.9
50
5.4
7.8
100
10.9
15.6
125
13.6
19.5
150
16.3
23.4
175
19.1
27.3
200
21.8
31.2
225
24.5
35.1
250
27.2
39.0
275
30.0
42.9
300
32.7
46.8
325
35.7
50.7
350
38.1
54.6
375
40.9
58.5
400
43.6
62.4
425
46.3
66.3
450
49.0
70.2
475
51.8
74.1
500
54.5
78.0
With other system volumes than shown above,
multiply the volume by the adjacent factors
0.109
0.156
Table 4.5 Size of an additional expansion vessel
4.8.6 Shift load storage tank expansion vessel
The shift load storage tank is fitted with a 1 litre expan-
sion vessel.
4.9
Details for the pumps
4.9.1 Circulation
pump
The circulation pump is integrated in the combi boiler.
The remaining head of the pump with respect to the
bypass valve is shown in Fig. 4.8.
The operating mode of the 2-speed pump can be
adjusted using diagnostic number d.19, see Section 9.1.2.
400
300
200
100
0
0
200
400
600
800 1000 1200
1600
Lift
[ mbar
]
Volumeflow [l/h]
1800
1400
2. Step
1. Step
2000
Fig. 4.8 Technical data of the pump in the combi boiler
4.9.2 Shift load storage tank circulation pump
The shift load storage tank is equipped with a mainte-
nance-free charging pump.
4.10 System-Bypass
The boiler is fitted with an automatic system by-pass.
The installation can be used in systems with thermo-
static radiator valves without the need for an additional
by-pass. The by-pass valve is adjustable, see Section
6.8.
4.11 Venting
The boiler is fitted with an automatic air vent. Other
measures need to be taken to allow the heating system
to be either automatically or manually vented during
filling and during commissioning.
4.12 Condensate
siphon
The boiler is fitted with a condensate siphon incorporat-
ing a water seal of 145 mm.
4 General requirements
Summary of Contents for ecoTEC plus 937
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