Vaillant ecoTEC plus 937 Instructions For Installation And Servicing - page 16
ecoTEC plus 937 installation and maintenance manual
16
3.10 System
requirements
3.10.1 Water circulation system
Detailed recommendations concerning the water
circulation system can be taken from BS 6798 and
BS 5449, Part 1 (for "Small Bore” and "Micro Bore”
central heating systems). Pipework which does not form
part of the usable heating surface should be insulated to
prevent heat losses and possible freezing up, especially
where the pipes run through roof spaces and ventilated
underfloor spaces. The drain connections must be
located in easily-accessible locations, so that draining
the entire system including the combi boiler and the hot
water system is possible. The drain connections should
be at least 1/2 " (BSP nominal size) and must be in
accordance with BS 2879.
The combi boiler is suitable for Minibore and Microbore
Systems. Copper tubing in accordance with BS 2871
should be used for all water carrying pipework. All
capillary joints in all Domestic Hot Water (DHW)
pipework must be made with lead free solder. When a
new boiler is to be fitted to an existing system, it is good
practise that the system is thoroughly flushed before
the boiler if installed in the system. See BS 7593 for full
details.
a
Caution!
To prevent the formation of deposits and
prevent serious damage to the appliance and
system, cleansers must be used carefully
following the cleanser manufacturers
instructions and must be removed by
thoroughly flushing the system. Cleansers
should only be left in systems for a maximum
of 24 hours. Failure to thoroughly remove
cleanser from a system could result in damage
to the appliance.
The cleaning must take place before fitting a new boiler
and in accordance with BS 7593. Recommendations for
use of system cleaning agents can be obtained from
Sentinel, Betz Dearborn Ltd. Widnes, Cheshire, WA8
8UD, Tel. 0151 420 9595, or Fernox, Alpha Fry
Technologies, Tandem House, Marlow Way, Croydon, CR0
4XS, Tel. 0870 8700362.
3.11.2 Filling and preparation of the heating system
The system can be filled using the incorporated filling
device. This connection must be removed again after the
filling process is complete. If the local Water Authority
regulations do not allow temporary connection a sealed
system filler pump with break tank must be used. The
heating system will not be filled automatically from the
domestic hot water side. (Alternative methods of filling
sealed systems are given in BS 5449))
3.10.3 Pressure relief valve
The boiler is equipped with a pressure relief valve. This
safety device is required for all sealed central heating
systems, is preset to 3 bar and is fitted with a 15 mm
compression connection for the discharge pipe, whose
diameter must not be less than 15 mm. The pressure
relief valve must not be used for draining purposes.
3.10.4 Pressure gauge
The pressure gauge is fitted to the boiler in the factory
and indicates the pressure of the primary circuit, to
make filling and testing easier.
3.10.5 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
modernising 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 3.5 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 3.3 Size of an additional expansion vessel
3 General requirements