Ariston AL01

Ariston error code AL01 indicates: Ariston Quadrio 4-Door Total NoFrost Refrigerator: Fresh food compartment evaporator NTC thermistor sensor fault AL01; circuit reading out of calibrated limits..

The primary root cause for Ariston code AL01 is: On Ariston refrigerators (Ariston Italian ergonomic chassis engineering and Bitron / EVO-II microprocessor bus platform): Water ingress into thermal sensor epoxy potting, fractured copper leads behind liner, or corrosion on terminal pin J1..

To resolve error code AL01: Unplug unit. Access sensor behind rear baffle. Measure NTC resistance: nominal ~2.7 kΩ at 25°C, ~7.8 kΩ at 4°C, ~16 kΩ at 0°C. Replace sensor probe. Press Alarm Reset button for 5 seconds to reset high-temperature acoustic warning and clear fault code.

Resetting power (unplugging for 5–10 minutes) clears temporary memory errors. However, if Ariston code AL01 persists, the physical component causing On Ariston refrigerators (Ariston Italian ergonomic chassis engineering and Bitron / EVO-II microprocessor bus platform): Water ingress into thermal sensor epoxy potting, fractured copper leads behind liner, or corrosion on terminal pin J1. must be inspected or replaced.

Set a digital multimeter to ohms (Ω). Disconnect power and test Compressor Motor Windings (Run/Start) & Defrost Heater across Across 3 compressor pins (Common, Run, Start): R(C-S) + R(C-R) = R(S-R). Winding to earth: >20MΩ (OL).. Expected nominal reading is 15Ω–25Ω (Run C-R), 20Ω–35Ω (Start C-S), 200Ω–400Ω (Defrost Heater). PTC Relay: 10Ω–30Ω at 25°C.. Tolerance: ±10%. Any low insulation resistance to casing (<2MΩ) trips the breaker. Defrost bimetal reads <0.5Ω when sub-zero..

Standard electrical safety protocol: 1. Disconnect 230V mains power before opening panels. 2. Verify zero voltage at test points. 3. Allow hot water or heating elements to cool below 30°C before handling.