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3.5.2. Cleansing and flushing the system
Flushing of system is highly recommended, this will prevent damage to the appliance made by dirt
from the system.
Particularly where a new boiler is to be fitted to an existing system, it is a good practice that
the system is thoroughly cleansed.
To prevent the formation
of deposits and
to
prevent serious damage to the appliance and system,
cleansers must be used carefully and must be completely removed by thoroughly flushing the system.
Cleansers should only be left in systems for the
maximum of 24 hours.
3.5.3. Filling and preparing heating system
A pressure relief valve is
provided with the boiler. This safety device is required on all sealed C.H.
systems and is preset at 2
.
5 bar and provided with a 15 mm compression 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.
3.5.5. Expansion vessel
T
h
ermoExtra
boilers are not equipped
with
an expansion vessel.
3.5.6. Circulating pumps
A c
irculation pump is
not
included in T
h
ermoExtra boilers
.
On the
electrical
switchboard mounted inside of T
h
ermoExtra boilers, there are terminals prepared
to pump
connection
(CH pump and/or DHW pump)
.
See electrical diagram for more details.
The system can be filled using the built
-
in filling valve or via a separate filling point fitted at a
convenient position on the heating 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
domestic hot water side.
Note:
For the heating system to operate properly the indicator of manometer must be between 1
.
2
and 1
.
5 bar when system is cold. It is very important to use soft water or fluids for central
heating.
Do not fill the system with water from private source.
3.5.4. Pressure relief valve
