Ariston Nuos Split Flex 150L User Manual (English)

Questions and Answers:

D
Dominique Nunez PhDAug 1, 2025
Why is the water from my Ariston Nuos Split Flex 150L cold?
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  Jacob PageAug 1, 2025
  If the water from your Ariston Water Heater is cold or not warm enough, there could be several reasons. First, check if the temperature setting is too low and increase it. There may be device functioning errors, so check the display for any error messages and follow the instructions provided. Ensure that the unit is properly connected to electricity, checking the voltage and cable connections. If you're using an HC/HP signal cable, try 'Boost' mode and inspect the meter and cable. For two-tier rate setups, verify the contactor and heating time. Also, check if 'Voyage' mode is active and deactivate it if necessary. Finally, ensure the product is turned on and check for probe errors, indicated by an E5 error.
K
Kayla EdwardsAug 5, 2025
What to do if Ariston Water Heater is leaking from the safety valve?
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  John MeltonAug 5, 2025
  A small drip from the safety valve of your Ariston Water Heater during heating is normal. To prevent this, consider installing an expansion vessel on the water supply. However, if the leakage persists when the unit isn't heating, inspect the device's calibration and the water network pressure. Important: Do not block the safety valve's evacuation hole!
B
Bobby FarrellAug 9, 2025
Why is the hot water flow from my Ariston Nuos Split Flex 150L weak?
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  Lisa FergusonAug 9, 2025
  If you're experiencing insufficient hot water flow from your Ariston Water Heater, check for leaks or obstructions in the water circuit. Inspect the deflector pipe and the incoming cold and hot water pipes for any damage.
J
johnstewartAug 14, 2025
What to do if Ariston Nuos Split Flex 150L Water Heater is producing boiling water?
- S
  Stephanie JohnsonAug 14, 2025
  If the water from your Ariston Water Heater is boiling, with steam coming from the taps, it could be due to a few reasons. A high level of scaling on the boiler and components can cause this. To resolve, turn off the power, drain the unit, remove the resistance sheath, and carefully remove limescale, being careful not to damage the enamel or sheath. Reassemble the product, replacing the flange gasket. A probe error, indicated by E5, could also be the cause. Air temperature out of range or a “Time W” value that is too low, can also cause this problem. To resolve, set a parameter for lower temperature or a longer unit of “Time W".
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William LevyAug 18, 2025
Why is the display of my Ariston Water Heater not working?
- E
  Emily YoungAug 18, 2025
  If you're experiencing display problems with your Ariston Water Heater, such as a blank screen, the issue might stem from damaged or disconnected wiring between the electronic and interface boards. Check the integrity of these connections and the operation of the electronic boards. Also, verify that the unit is receiving power from the mains and, if applicable, check the condition of the batteries.

Ariston Nuos Split Flex 150L Specifications

General

Type	Heat Pump Water Heater
Capacity	150 Liters
Brand	Ariston
Model	Nuos Split Flex 150L
Energy Efficiency Class	A+
Maximum Operating Pressure	8 bar
Temperature Adjustment	Electronic
Power Supply	230V/50Hz
Max Temperature	75°C
Thermal Insulation	Polyurethane
Safety Features	Thermal Cut-Out