Technical data

20 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
]
18001400
2. Step1. 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