Maintenance; General Remarks; Anti-Freeze Function; User Information - Ariston NIMBUS HYBRID MODULE UNIVERSAL NET Manual

INSTALLATION WITHOUT BOILER.
In case of installation without auxilary heat generator, connect
hydraulically the module to the outdoor unit and to the heating
system and plug the connections not used.
Set the parameter 916 to "External heat request".

MAINTENANCE

Note: other important information regarding product mainte-
nance are given in the boiler manual.
Maintenance is an essential operation for safety, correct boiler
operation, 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 replace-
ments.
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.
7. Inspection of the expansion vessel pressure.
8. The front grille and battery pack of the external unit must be
kept clean.
WARNING
Empty all components that could contain residual hot
water before handling them.
Descale the components, by following the instructions
indicated on the descaling agent used.
Perform this operation in a ventilated space, while wear-
ing appropriate safety equipment; avoid mixing deter-
gents and protect the equipment and surrounding ob-
jects.

User information

Inform the user on how to operate the installed system.
In particular, hand this instruction manual to the users, in-
forming them that is must be kept near the product at all
times.
Inform potential users that the following actions must be
carried out:
• Periodically check the system water pressure
• Restore system pressure, by deaerating the system
when necessary
• Adjust the setting parameters and the adjustment de-
vices to optimise operation and reduce the system's op-
erating costs
• Perform regular maintenance, as envisaged in the stand-
ards.
90 /
Anti-freeze function of the external unit
The primary circulator of the external unit starts at the
minimum speed when the water return temperature (EWT)
measured by the sensor falls below 7°C in heating mode.
Or when the sensor that measures the delivery tempera-
ture (LWT) gives a reading below 10°C in heating mode or
below 1°C in cooling mode.
The primary circulator stops when the water return tem-
perature (EWT) exceeds 8°C in heating mode. Or when the
delivery temperature (LWT) exceeds 10°C in heating mode
or 4°C in cooling mode.
If the LWT sensor malfunctions, the protection logic will be
based on the values measured by the external tempera-
ture sensor (OAT) of the external unit.
The primary circulator starts when the external tempera-
ture sensor gives a reading above 7°C in heating mode.
The primary circulator stops after 30 sec or when the ex-
ternal temperature sensor gives a reading above 8°C in
heating mode.
This check is repeated every 15 minutes.
Anti-freeze function of the hybrid module
The primary circulator of the external units starts at the
maximum speed when the temperature measured by the
"CH Flow" sensor falls below 7°C in heating mode.
If the temperature is still below 9°C after 5 minutes, the
heat pump's compressor will start working at 50% of the
frequency.
If the temperature is still below 9°C after 25 minutes, the
boiler is activated.
The boiler runs its anti-freeze functions.
The primary circulator stops when the temperature meas-
ured by the "CH Flow" sensor rises above 9°C in heating
mode.