Ariston NUOS PLUS 250 TWIN SYS User Manual

33 / EN
CAUTION!
Before intervening on the product by following the indications below, check the correct electrical connection of the components to the
mainboard and the correct position of the NTC sensors in their seats.
Error code Cause Heating element operation Heat pump operation What to do
007 NTC Condenser: Open or Short Circuit ON OFF Verify NTC Condenser proper functioning
008
NTC Discharge (Compressor Outlet):Open or Short
Circuit
ON OFF Verify NTC Discharge proper functioning
009 NTC Air: Open or Short Circuit ON OFF Verify NTC Air proper functioning
010 NTC Evap: Open or Short Circuit ON OFF Verify NTC Evap proper functioning
012 NTC Suction (Compressor Inlet): Open or Short Circuit ON OFF Verify NTC Suction proper functioning
021 Gas Leak ON OFF
Verify compressor inlet sensor proper functioning. If the error persists,
recover residual gas; find the leak in the cooling circuit; repair it; make
vacuum and recharge circuit with 1100g of refrigerant gas
032 Compressor Issue ON OFF Check power voltage on compressor connector.
042 Evaporator Obstructed ON OFF
Turn o the appliance.
Check that the evaporator and the external unit casing is not obstructed.
044 Fan Issue ON OFF
Check power voltage on fan connector.
Control the proper functioning of sensor at compressor inlet.
051 High Pressure ON OFF Check pressure switch wiring. Verify gas quantity.
053 Compressor Thermal Protector: KO ON OFF Check compressor thermal protector connector.
081 Electronic Expansion Valve Issue ON OFF
Verify expansion valve cables. Verify NTC suction and NTC Evap correct
functioning.
218 Dome NTC sensor (hot water): Open or Short Circuit ON OFF Verify NTC sensor (hot water) proper functioning
230
Water Temperature Sensor (Heating Element Zone):
Open or Short Circuit
OFF OFF
Check the correct assembly of sensor wiring on related mainboard
connector.
Verify sensor proper functioning.
231
Water Temperature sensor (Heating Element Zone):
safety intervention (1st level).
OFF OFF Verify sensor proper functioning.
232
Water Temperature sensor (Heating Element Zone):
safety intervention (2nd level).
OFF OFF Verify sensor proper functioning.
233 Relay blocked OFF OFF
Reset the appliance by pressing the ON/OFF button twice. If the error per-
sists, replace the motherboard.
241 Impressed Current Anode: Open Circuit OFF OFF
Check the presence of water inside the product.
If the error persists, verify the anode proper functioning. Check the correct
assembly of anode wiring on related mainboard connector.
If the error persists, replace mainboard.
DEFAULT SETTINGS
The appliance is manufactured with a series of default modes, functions or values, as indicated in the table below:
PARAMETER FACTORY DEFAULT SETTING
WORKING MODE GREEN
DEFAULT SET TEMPERATURE 53 °C
MAX. TEMPERATURE SETTABLE WITH THE HEATING ELEMENT 75 °C
MINIMUM SETTABLE TEMPERATURE 40 °C
MAX. TEMPERATURE SETTABLE WITH THE HEAT PUMP 62 °C
ANTI-LEGIONNAIRE’S DISEASE PROTECTION DEACTIVATED
HOLIDAY MODE DEACTIVATED
DEFROST (active defrost activation) ACTIVATED
HC-HP (two-tier rate operation mode) DEACTIVATED
HYSTERESIS 12°C
FAULTS
As soon as a fault occurs, the appliance enters into the fault mode while the display emits flashing signals and visualises the error code. The wa-
ter heater will continue supplying hot water if the fault aects only one of two the heating units, by activating the heat pump or heating element.
If the fault involves the heat pump, the symbol "HP" will flash on the screen, while the heating element symbol will flash if the fault involves it. If
both components are aected, both symbols will flash.

Ariston NUOS PLUS 250 TWIN SYS Specifications

General

Brand	Ariston
Model	NUOS PLUS 250 TWIN SYS
Category	Water Heater
Language	English