Maintenance; General Remarks; Operation Test; Anti-Freeze Function - Ariston NIMBUS EXTERNAL UNIT 04 kW Technical Instructions For Installation And Maintenance

NSTALLATION WITHOUT BOILER.
In case of installation without boiler, make the hydraulic connections
to the heat pump and the heating system as described. Seal all the
remaning connections.
Set the parameter 916 to "External heat request".

MAINTENANCE

Note: other important information regarding product maintenance are
given in the boiler manual.
Maintenance is an essential operation for safety, correct boiler opera-
tion, and system durability.
It must be carried out in accordance with applicable regulations.
You should regularly check the refrigerant gas pressure.
Before beginning maintenance work:
• Disconnect the system power supply
• Close the circuit heating water and domestic hot water taps.

General remarks

It is necessary to carry out the following checks at least once a year:
1. Visual inspection of the general state of the system.
2. Inspection of hydraulic system seal and any gasket replacements.
3. Inspection of the refrigerant gas seal.
4. Carry out a general inspection of the system operation.
5. Check the heating circuit pressure.
6. Check the expansion vessel pressure.

Operation test

After maintenance operations, proceed with the refi lling of the heat-
ing circuit to the recommended pressure and deaerate the installation.
Drain heating/cooling circuit or anti-freeze products use
If you plan to install the system in areas where the temperature could
drop below 0°C, it is advisable to add liquid anti-freeze to the system
water in order to limit the drainage required. Where anti-freeze liquid
is used, check its compatibility with the stainless steel from which the
external unit plate heat exchanger is constructed.
We recommend the use of anti-freeze products containing propyl-
ene glycol anti-corrosion (e.g. CILLICHEMIE CILLIT CC 45, non-toxic,
with anti-freeze, corrosion and build-up protection), in the dosages
recommended by the manufacturer and in accordance with the tem-
peratures required for the zone.
Regularly check the pH level of the anti-freeze mix in the circuit and
ensure that the value measured is lower than the limit prescribed by
the manufacturer.
DO NOT MIX DIFFERENT TYPES OF ANTI-FREEZE LIQUID.
The manufacturer is not liable for damage to the system caused by
the lack of use of anti-freeze or the use of inappropriate additives.

Anti-freeze function

External unit anti-freeze protection.
The HYBRID MODULE primary circulation pump is activated if the re-
turn water temperature to the external unit is equal to or less than 7
°C for more than two consecutive minutes.
If the temperature reaches and exceeds 8 °C for more than two con-
secutive minutes, the circulation pump is switched off.
Should the system return temperature sensor malfunction, the func-
tion is activated by referring to the system delivery temperature sen-
sor values.
If the external unit anti-freeze function is insuffi cient, the system au-
tomatically enables the HYBRID MODULE anti-freeze protection.
In this case also, the HYBRID MODULE primary circulation pump is
activated if the return water temperature to the external unit is equal
to or less than 7 °C for more than two consecutive minutes. If the
temperature reaches and exceeds 9 °C for more than two consecu-
tive minutes, the circulation pump is switched off.
Should the system return temperature sensor malfunction, the func-
tion is activated by referring to the system delivery temperature sen-
sor values.
If the water circulation is insuffi cient to ensure the anti-freeze func-
tion, the system controls switch on of the external unit and of the
electrical heating elements automatically.
WARNING
Empty all components that could contain residual hot water before
handling them.
Decalcify components, following the instructions on the descaling
agent used.
Do this in a ventilated space, wearing the necessary safety equip-
ment, avoiding mixing detergents, and protecting the equipment and
surrounding objects.

User information

Inform the user on how to operate the installed system.
In particular, give the user the instruction manual, informing him of the
need to keep it near the product.
Please inform the user on the need to proceed with the following ac-
tions:
• Periodically check the system water pressure
• Restore system pressure, deaerating it when necessary
• Adjust the setting parameters and the adjustment devices in order
to obtain better operation and a more economical system
• Carry out, as required by standards, regular maintenance
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