Water Flow Control; Space Heating And Dhw; Additional Hydraulic Necessary Elements For Space Heating - Hitachi YUTAKI S Series Installation And Operation Manual

• The internal air pressure of the expansion vessel tank will be adapted to the water volume of
the final installation (factory supplied with 0.1 MPa of internal air pressure).
• Do not add any type of glycol to the water circuit.
• Drain taps must be provided at all low points of the installation to permit complete drainage of
the circuit during servicing.
5.3.5 Water flow control
YUTAKI pumps can estimate the water flow by electronic calculation. Therefore, there is no need to
install a water flow switch with the new YUTAKI pumps.
However, if a secondary pump is installed or glycol is used (in the case of YUTAKI M), it is necessary
to install a water flow control, as the electronic calculation may be affected.
5.4

Space heating and DHW

!
DANGER
Do not connect the power supply to the indoor unit prior to filling the space heating circuit (and
DHW circuit if it were the case) with water and checking water pressure and the total absence of
any water leakage.
5.4.5.1 Additional hydraulic necessary elements for space heating
Nature
Piping connections
Factory supplied
Accessories
Field supplied
PMEN0643 rev.0 - 04/2023
No.
1 Water inlet (Space heating)
2 Water outlet (Space heating)
3 Shut-off valve (factory-supplied)
Water check valve
4
(ATW-WCV-01 accessory)
5 Shut-off valve
Part name
5
26