Ariston AL02

Ariston error code AL02 indicates: Ariston Quadrio 4-Door Total NoFrost Refrigerator: Freezer evaporator defrost termination NTC sensor fault AL02; controller unable to detect coil temperature..

The primary root cause for Ariston code AL02 is: On Ariston refrigerators (Ariston Italian ergonomic chassis engineering and Bitron / EVO-II microprocessor bus platform): Thermal shock degradation, moisture saturation inside sensor jacket during defrost cycles, or severed clip-on lead..

To resolve error code AL02: Disconnect power. Remove freezer evaporator cover. Check NTC resistance: ~2.7 kΩ at 25°C, ~16 kΩ at 0°C, ~32 kΩ at -18°C. Replace clip-on defrost sensor. 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 AL02 persists, the physical component causing On Ariston refrigerators (Ariston Italian ergonomic chassis engineering and Bitron / EVO-II microprocessor bus platform): Thermal shock degradation, moisture saturation inside sensor jacket during defrost cycles, or severed clip-on lead. 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.