Routine Maintenance; Troubleshooting - Ariston NUOS Manual

Heat pump water heater - OPERATING AND MAINTENANCE INSTRUCTIONS FOR THE USER

8.2 Routine maintenance

Partial obstruction of the evaporator filter causes a reduction in product performance. We therefore recommend
cleaning the filter to remove any dust or obstructions at least once a year. The filter can be extracted using the
appropriate clip above the casings (fig. 17). Clean the filter with water and mild soap.
Verify that the external terminal of the air exhaust duct, and the duct itself, are not obstructed or have not deteriorated.
Ensure that the condensate water runs out in a suitable drain and make sure the discharge is made without
hindrance.
Check and clean canalizations and grills.

8.3 Troubleshooting

Problem
Low temperature set
Device functioning errors
No electrical connection, disconnected or
damaged wirings
Absence of HC/HP signal (if the product is
Water comes
installed with the HC/HP signal cable)
out cold or
Malfunctioning of the timer for two-tier rate (if the
insufficiently
warm product is installed in this configuration)
Insufficient air flow to the evaporator.
Product off
Usage of a large amount of hot water when the product is heating up phase.
Probe error
The water is
boiling (with
High level of scaling of the boiler and
the possible
components
presence of
steam from
the taps)
Probe error
Air temperature out of range
"Time W" value too low
Reduced
functioning of
Installation done not in accordance with electric
the heat
voltage (too low)
pump, semi-
Evaporator clogged or frozen
permanent
operation of
Problems with the heat pump circuit
the electrical
Are not yet past 8 days by:
resistance
-First Time instalation.
-Change of the parameter Time-W.
-No power from mains in absence of batteries or exhausted batteries.
Insufficient
flow of hot Leaks or obstructions by the water circuit
water
Overflowing
A drip of water by the device should be
water by the
the safety considered normal during the heating
valve
Presence of obstructive elements inside
Increase of
the noise
Components vibration
Possible reason
84
What to do
Increase the temperature set for the outlet water.
Check for errors on the display and act in the way specified
on the chart "Faults".
Check the voltage at the supply terminals, verify the
integrity and connections of the cables.
Try to put the product in "Boost" mode, if is ok in this way,
check the connection of the meter, check the integrity of the
HC/HP cable.
Check the operation of the contactor day / night and that
the set time is enough to heat water.
Clean the grilles and ducts regularly.
Check availability of electricity, turn on the product.
Control the presence, even if occasional E5.
Turn off the power, drain the unit, remove the sheath of the
resistance and remove lime scale inside the boiler, be
careful not to damage the enamel of the boiler and the
sheath resistance. Repackage the product as in the original
configuration, it is recommended to replace the flange
gasket.
Control the presence, even if occasional E5.
Depending from the climatic conditions.
Set a parameter for lower temperature or a longer unit of
"Time W".
Provide a proper Electric voltage.
Check the cleaning of the evaporator.
Make sure that there are no errors on the display.
Verify that there are no leaks along the circuit, check
the integrity of the the deflector pipe, the integrity of
incoming cold water pipe and hot water pipe.
If you want to avoid the drip, install an expansion vessel on
the plant supply.
If leakage continues during the period of no heating, check
the calibration of the device and the pressure of the water
network. Caution: Do not obstruct the hole for evacuation of
the device!
Check the components in movement, clean the fan and the
other parts who can generate noise or vibrations.
Check the components fixed with screws, be sure that the
screws are tight.