It is also necessary to analyse the quality of water by checking pH, electrical conductivity, ammonia ion content, sulphur content, and others. Should

the results of the analysis be not good, the use of industrial water would be recommended.

•

No antifreeze agent shall be added to the water circuit.

•

To avoid deposits of scale on the heat exchangers surface it is mandatory to ensure a high water quality with low levels of CaCO

Recommendations for the DHW circuit

The following is the recommended standard water quality.

Item

Electrical Conductivity (mS/m) (25°C)

{µS/cm} (25 °C)

(2)

Chlorine Ion (mg CI¯/I)

Sulphate (mg/l)

Combination of chloride and sulphate (mg/l)

Total Hardness (mg CaCO

/I)

N O T E

•

(1): The mark " " in the table means the factor concerned with the tendency of corrosion or deposits of scales.

•

(2): The value shown in "{}" are for reference only according to the former unit.

•

(3): Water range will be according s/UNE 112076:2004 IN.

6.5.3.1 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.

N O T E

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.

PMML0575 rev.2 - 03/2022

DHW space

Water supplied

(3)