Vaillant ecoTEC pro 24, Instructions For Installation And Servicing

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Instructions for installation and servicing ecoTEC / 839592_09
3.10 Guide to system requirements
3.10.1 Water circulation system
Detailed recommendations for the water circulation sys-
tem are given in BS 6798 and BS 5449: Part 1 (for small
bore and micro bore central heating systems). Pipework
not forming part of the useful heating surface should be
insulated to help prevent heat loss and possible freezing,
particularly where pipes are run through roof spaces
and ventilated underfloor spaces. Draining taps must be
located in accessible positions which permit the draining
of the whole system including the boiler and the hot
water system. Draining taps should be at least 1/2 in.
BSP nominal size and be in accordance with BS 2879.
The boiler is suitable for use with minibore or microbore
systems. Copper tubing to BS 2871: Part 1 should be used
for water carrying pipework. All capillary joints in all
DHW pipework must be made with lead free solder.
Particularly where a new boiler is to be fitted to an exist-
ing system, it is good practice that the system is thor-
oughly cleansed.
Caution!
To prevent the formation of deposits and pre-
vent serious damage to the appliance and sys-
tem, cleansers must be used carefully and must
be completely removed by thoroughly flushing
the system. Cleansers should only be left in
systems for a maximum of 24 hours.
This cleansing must take place prior to the fitting of the
new boiler and be in accordance with BS 7593. For
advice on the application of system cleansers contact
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.
3.10.2 Filling and preparing heating system
The system can be filled using the built in filling loop
(ecoTEC plus combination boilers only) or via a separate
filling point fitted at a convenient position on the heat-
ing circuit. The connection must be removed when filling
is completed. Where local Water Authority regulation
does 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 domes-
tic hot water side. (Alternative methods of filling sealed
systems are given in BS 5449).
3.10.3 Pressure relief valve
A pressure relief valve is provided with the boiler. This
safety device is required on all sealed C.H. systems and
is preset at 3 bar and provided with a 15 mm compres-
sion connection for a discharge pipe, which must be of
no less than 15 mm in diameter. The pressure relief
valve must not be used for draining purposes.
3.10.4 Pressure gauge
This is factory fitted to the boiler and indicates the pri-
mary circuit pressure to facilitate filling and testing.
3.10.5 Expansion vessel
ecoTEC boilers incorporate a 10 litre expansion vessel
which is suitable for a sealed heating system with a
maximum water content of 100 litres.
If the nominal capacity of the built in expansion vessel is
not sufficient for the heating system (for instance in
case of modernisation of old open systems) an addition-
al expansion vessel can be installed external to the boil-
er. It should be fitted in the return pipe as close as pos-
sible to the boiler in accordance with BS 5449: Part 1.
Guidance on the sizing of an additional expansion vessel
is given in Table 3.5.
Vessel Volume [L]
Initial system pressure (bar) 1.0 1.5
Pressure relief valve setting (bar) 3.0
Total water content of system litres
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
For system volumes other than those given
above, multiply the system volume by the
factor across
0.109 0.156
Table 3.5 Sizing of additional expansion vessel
3.11 Pump specifications
3.11.1 Circulating pump
only ecoTEC plus:
The circulating pump is included in the boiler. The residual
pump discharge height depending on the by-pass valve is
shown in Fig. 3.10.1 (ecoTEC plus) and 3.10.2 (ecoTEC plus
637 / 837).
The operating mode of the 2-step pump can be adjusted
below the diagnosis number “
d.19 ”, see section 8.1.2.
General requirements 3