Ariston Dishwasher Error Code AL 08

AL 08 is a heating timeout fault on Ariston dishwashers. It triggers when the control board detects that the wash water temperature has failed to reach the required setpoint within a 60-minute window. The heating circuit relies on two core components working together: the heating element, which raises water temperature, and the NTC (Negative Temperature Coefficient) thermistor, which continuously reports the actual water temperature back to the control board. If the board does not see the expected temperature rise within the allotted time, it locks the cycle and displays AL 08.

The most common starting point for diagnosis is the NTC thermistor itself. If the NTC has become detached from its mounting position on the sump casing, it may be reading ambient or air temperature rather than water temperature, causing the board to believe heating is not occurring even if the element is functioning normally. A miscalibrated or faulty NTC will send incorrect resistance values to the control board, producing the same timeout result. At operating temperatures, a healthy NTC should show a predictable resistance drop as temperature rises, so measuring resistance across the sensor terminals at a known temperature is a reliable test.

Beyond the NTC, the heating element itself should be tested for continuity and proper resistance. An open or partially failed element will not heat water adequately regardless of what the NTC reports. Wiring connections to both the element and the NTC are also a key inspection point, as corroded or loose terminals can interrupt the circuit without any visible component failure. Insufficient water fill or a faulty water inlet valve can also contribute by leaving the element partially exposed, though the NTC and element connections are the primary suspects.