Hitachi YUTAKI S Series Installation And Operation Manual

22
PMEN0643 rev.0 - 04/2023
5
WATER PIPING
REFRIGERANT AND WATER PIPING
◆ Addional DHW Circuit recommendaon
In places where possible hard water areas, to prevent and minims scale situaons, it is
recommended to reduce stored water temperature to a maximum of 55°C, as huge scale quanty
could damage the water tank and the electrical heater.
Flush the domesc water circuit with at least 10 mes its volume of water. The life of the water
tank will be shorter if groundwater (spring water, well water, etc..) is used without treatment which
can lead to the corrosion of the tank. The water must not be aggressive or encrusng at any me.
The result of calculang the Langelier Index should be between +/- 0.5.
In installaon locaons where the result of Langelier Index calculaon are out of the expected
value with a tendency to corrosive water, it is recommended to install an acve anode accessory.
In the regions where the water is very hard (or out of requirements values) or where the result
of Langelier Index calculaon are out of expected value with a tendency to hard water, it is
recommended ng a soener system. Please ensure that soener system will be capable of
providing eecve protecon against corrosion. It is recommended to install an acve anode
accessory.
As DHW Tank water is being used for storing drinking water, this water has to be in accordance
with naonal regulaons and Hitachi’s quality minimum requirements. The use of soeners, acve
anodes or others protecve systems will not bring a derogaon from Hitachi’s provided warranty.
5.3.3.1 Water lling
◆ Space heang
1 Check that a water check valve (ATW-WCV-01 accessory) with a shut-o valve (eld supplied)
is connected to the water lling point (water inlet connecon) for lling the space heang
hydraulic circuit (see “5.4 Space heang and DHW”).
2 Make sure all the valves are open (water inlet/outlet shut-o valves and the rest of valves of the
space heang installaon components).
3 Ensure that the air purgers of the indoor unit and installaon 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 lling procedure.
5 Fill the space heang circuit with water unl the pressure displayed on the manometer reaches
approximately 1.8 bar.
 NOTE
While the system is being lled with water, it is highly recommended to operate the safety valve
manually so as to help with the air purging procedure.

Hitachi YUTAKI S Series Specifications

General

Brand	Hitachi
Model	YUTAKI S Series
Category	Heat Pump
Language	English