Hitachi YUTAKI S80 Series Instruction Manual page 23

REFRIGERANT AND WATER PIPING
4.3.5
Indoor unit
Space heating
1 Check that a water check valve (ATW-WCV-01 accessory)
(see "4.3 Space heating and
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 air purger are driven to the base hole near the heat
exchanger. In case of the drain pipe for safety valve, place
it as far as possible from the indoor unit (see
procedure"). The excessive water will be expelled by it.
Fill the space heating circuit with water until the pressure
displayed on the manometer reaches approximately 1.8 bar.
N O T E
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:
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
installation has been removed, a reduction of water pressure
in the circuit is very likely to occur. Therefore, additional
approximate level of 1.8 bar.
13 PMML0340B rev.1 - 03/2016
DHW").
"Installation
N O T E
• The indoor unit is equipped with an automatic air purger (factory
supplied) at the highest location of the indoor unit. Anyway, if there
are higher points in the water installation, air might be trapped inside
water pipes, which could cause system malfunction. In that case,
no air enters into the water circuit. The air vents should be located at
points which are easily accessible for servicing.
• The water pressure indicated on the indoor unit manometer may vary
depending on the water temperature (the higher temperature, the
higher pressure). Nevertheless, it must remain above 1 bar in order
to prevent air from entering the circuit.
• Fill in the circuit with tap water. The water in the heating installation
must comply with EN directive 98/83 EC. Non-sanitary controlled
water is not recommended (for example, water from wells, rivers,
lakes, etc.) (See "Water quality"
• The maximum water pressure is 3 bar (nominal opening pressure of
the safety valve). Provide adequate reduction pressure device in the
water circuit to ensure that the maximum pressure is NOT exceeded.
•
pump and an open circuit to prevent the formation of air pockets.
• Check carefully for leaks in the water circuit, connections and circuit
elements.
Domestic hot water tank
If a domestic hot water tank has been installed, perform the
following operations:
Heating coil circuit
Fill the DHW tank heating coil from the space heating circuit
chapter to correctly perform the operation.
C A U T I O N
• Check that the heating coil pipes are correctly connected between
• Ensure the correct water quality of the indoor unit water circuit.
Domestic hot water tank and DHW circuit
1 Open the outlet water taps of the DHW installation one after
each other, to expel all the air from inside the water circuit.
2
there is a shut-off valve installed in the DHW outlet, open it
to allow circulation through the DHW installation.
3
DHW installation, close all these taps.
4 Finally, close the main DHW inlet valve when the pressure
reaches approximately 6 bars.
C A U T I O N
• Check carefully for leaks in the water circuit, connections and circuit
elements.
• Check that the water pressure in the circuit is lower than 7 bars.
• A pressure and temperature relief valve should be installed at the
DHW inlet connection of the tank (See
necessary elements for DHW"
discharge pipe.
• Fill in the circuit with tap water. The water in the heating installation
must comply with EN directive 98/83 EC. Non-sanitary controlled
water is not recommended (for example, water from wells, rivers,
lakes, etc.) (See "Water quality"
section at the CD-ROM).
"4.3.2 Additional hydraulic
section). If it is the case, manually
section at the CD-ROM).