Water Filling - Hitachi YUTAKI S80 R410A Series Installation And Operation Manual

5.3.3.1 Water filling
Space heating
◆
1 Check that a water check valve (ATW-WCV-01 accessory) with a shut-off valve (field supplied)
is connected to the water filling point (water inlet connection) for filling the space heating
hydraulic circuit (see
2 Make sure all the valves are open (water inlet/outlet shut-off valves and the rest of valves of the
space heating installation components).
3 Ensure that the air purgers of the indoor unit and installation are open (turn the indoor unit air
purger twice at least).
4 Check that the drain pipes connected to the safety valve (and to the drain pan in case of
installing the "Cooling kit" accessory) are correctly connected to the general draining system.
The safety valve is later used as an air purging device during the water filling procedure.
5 Fill the space heating circuit with water until the pressure displayed on the manometer reaches
approximately 1.8 bar.

NOTE
While the system is being filled with water, it is highly recommended to operate the safety valve
manually so as to help with the air purging procedure.
6 Remove as much air from inside the water circuit as possible through the indoor air purger and
other air vents in the installation (fan coils, radiators...).
7 Start the air purge procedure test. There are two modes (Manual or Automatic) which helps in
case of installations with heating and DHW operation:
a. Manual: Start and stop the unit manually using the unit controller (Run/Stop button) and
also using the DSW4 pin 2 of the PCB1 (ON: Forced to derive to DHW coil; OFF: Forced to
derive to space heating).
b. Automatic: Select the air purge function using the user controller. When the automatic
air purge function is running, the pump speed and the position of the 3-way valve (space
heating or DHW) are automatically changed.
Water
pump
DHW
3Wv
8 If a little quantity of air is still remaining in the water circuit, it will be removed by the automatic
air purger of the indoor unit during the first hours of operation. Once the air in the installation
has been removed, a reduction of water pressure in the circuit is very likely to occur. Therefore,
additional water should be filled until water pressure returns to an approximate level of 1.8 bar.
PMEN0648 rev.0 - 03/2023
"5.4 Space heating and
ON
OFF
DHW").
Repeat...
Repeat...
Seconds
Seconds
5
32