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2. For the Installer
2.2 System
2.2.1 Area of use
For heating buildings acc. to EN 12831.
The boilers are designed and approved as heat generators for hot water heating systems with a permissible flow
temperatures of up to 90°C. They may be installed only in sealed systems. The maximum flow temperature is
factory-set at 75°C.
2.2.2 Standards
The following European standard should be followed: EN 12828, this specifies that the following should be fitted:
a) A closed expansion tank.
b) A reliably functioning safety valve installed at the highest point of the boiler or at a non-closable line.
c) A thermometer, a pressure gauge.
d) A low-water cut-off: A low-water cut-off is not required for systems providing up to 300 kW nominal thermal
output, if it can be assured that excess heating will not result from a lack of water in the system.
If the boiler is above the radiators, then a low-water cut-off must be installed.
e) Only relates to boiler models with a thermal safety device:
An automatic device for dissipating heat which will prevent the maximum permitted operating temperature
from being exceeded. The built-in thermal safety device (not present with all boiler models) should always be
used with the thermal process safeguard.
2.2.3 Heating circuits
A motorised mixing valve is always required for the BioWIN in order to protect the boiler and one must be fitted in
each heating circuit. A feed contact thermostat (FK-001) must be installed for underfloor circuits.
2.2.4 Circulation pump
We recommend using pumps efficiency class A
2.2.5 Return temperature
The return flow temperature increase installed as standard means that BioWIN can be operated with a return
temperature down to min. 20 °C. No external return flow temperature increase is required.
Exception: Systems with a buffer in which the buffer is loaded directly from BioWIN with a return hold-up group.
2.2.6 Accumulator tank
In principle a pellet boiler system does not need an accumulator tank. A guaranteed minimum heat consumption
is required, e.g. fit a consumer circuit that cannot be blocked off or do not fit thermostat valves on all radiators.
The BioWIN 100–260 needs a buffer if:
– the total heating requirements of the building according to the ÖNORM M 7500 or EN 12831 calculation are less
than 50 % of the boiler‘s nominal output.
Information!
If using a buffer, the BioWIN return flow temperature must be increased – see hydraulic diagram in
the planning documents.
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