Ariston water heater shows E08; unit may overheat or not regulate temperature correctly.

Safety first: Turn off power and allow the heater to cool.

• Locate outlet sensor: On many Ariston models, a separate NTC is clipped to the hot water outlet pipe.
• Check mechanical contact: Ensure the sensor is firmly clamped to the pipe with thermal paste or a tight clip. A loose sensor can misread temperature.
• Inspect wiring: Follow the sensor wires back to the control board. Look for damage or loose connectors. Reseat the plug.
• Test sensor: Disconnect and measure resistance at room temperature and compare with the tank NTC if they are the same type. Large discrepancies indicate a faulty sensor.
• Replace sensor: Install a new Ariston-compatible outlet NTC, ensuring correct placement and secure attachment.

After replacement, clear the error by cycling power and verify stable outlet temperature.