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21
AST 14 C 255/00
3.2 HYDRAULIC UNIT
MOTORISED THREE-WAY VALVE
(only for CTFS version)
The boiler uses a three-way valve to divert the water flow coming from the primary
exchanger into another pipe, in particular it diverts the water into the secondary (plate)
exchanger, where heat will be transferred to the DHW.
This valve consists of one main brass three-way body, one plastic (thermosetting
polymers) cartridge, and one electric motor (actuator) to move the internal shutter.
The secondary exchanger is fixed by the three-way valve and another unit made of
thermosetting polymers connecting the cold water inlet pipe to the rest of the hydraulic
system.
The stainless steel plate exchanger consists of 26 plates for all versions: 24, 28 and 32
kW.
When domestic hot water is required, the cold water coming from the domestic water
system passes through the flowmeter, setting the boiler to "DHW" mode. Then the three-
way valve diverts the hot water coming from the primary exchanger into the secondary one
so that it can transfer its heat to the plates for the instantaneous production of domestic
hot water.
N.B.
In rest condition, the three-way valve is in DHW mode position.
Electric
motor
Water inlet from primary
exchanger
Outlet to plate
exchanger
Flow water
MOTOR CONNECTIONS
ELECTRICAL
1 Line 1
Central heating
2 Neutral
Domestic hot
water
