ATTACK WOOD&PELLET 25 Instructions For Use Manual page 17

Boiler protection against overheating
Every wood gasifying boiler must be fitted with a functional aftercooling circuit. The appropriate
valve ensuring this function can be ordered as an accessory. On the pic. 5 you can see the correct
installation of the valve of the aftercooling circuit.
DANGER! Following the norm EN303-5, the aftercooling circuit against overhetaing
must not be used for other purpose than the boiler protection against overheating.
Pic. 5 Connection of the thermostatic valve to the aftercooling loop
The valve must be permanently opened at the cold water inlet into the boiler aftercooling cir-
cuit. The aftercooling circuit must be connected to the functional distribution of the cooling wa-
ter (e.g. to the distribution of the cold water in the water supply network) with the temperature
of 10 – 15 °C and operating overpressure of 2 – 6 bar, ensuring the safe operation even by
a power failure.
The thermostatic valve at the outlet of the aftercooling circuit with the sensor placed in the rear
side of the boiler protects the boiler in the following way. If temperature of the water in the boil-
er exceeds 95 °C, the valve fills the aftercooling circuit with the water from the water supply
network to absorb the excessive heat. For the case that the boiler gets overheated and the
thermostatic valve is open, it is necessary to ensure the permanent outtake of the warm water
from the aftercooling circuit into the waste. Functionality of the aftercooling circuit and the
thermostatic valve can be checked manually, by the manual button of the thermostatic valve.
DANGER! If the circulation of the cooling water through the aftercooling circuit is
not ensured, when the thermostatic valve is open, there is a danger of the boiler
damage! The warranty is not valid in such a case.
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