Machine displays AL2 and steam function is disabled; steam boiler does not heat.

Safety first: Switch OFF, unplug, and allow the machine to cool fully. Steam boilers can remain dangerously hot and pressurized for a long time.

• Reset and observe: After cooling, plug in and restart. If AL2 appears immediately, proceed with inspection.
• Locate the steam boiler probe: Remove the top cover. Identify the larger boiler (steam boiler) and locate the NTC probe screwed into its body with two wires leading to the board.
• Check wiring and connectors: Inspect the harness for burns, cuts, or melted insulation. Ensure the connector at the control board is firmly seated. Reseat the connector several times.
• Check for leaks: Look for water or scale around the probe fitting. Any leak can damage the sensor and wiring. If leaking, the probe and/or sealing washer should be replaced.
• Measure resistance (advanced): Disconnect the probe from the board and measure resistance with a multimeter. Compare to the brew boiler probe at similar temperature. A reading of open or near-zero ohms indicates a failed probe.
• Replace components: Install a new Lelit steam boiler NTC temperature probe if faulty. If the probe tests good but AL2 persists, the main control board may need replacement by a qualified technician.