Display shows A06, burner shuts down during operation, often after running for a short period.

Safety: Turn off power and allow the unit to cool before touching pipework or internal components.

• 1. Check water flow: Open a hot tap fully and observe flow. Very low flow can cause rapid overheating. Clean or replace inlet filters and aerators on taps.
• 2. Inspect system valves: Ensure all isolation valves on the cold inlet and hot outlet of the Ferroli heater are fully open.
• 3. Descale heat exchanger: In hard water areas, the plate or primary heat exchanger can scale up. A technician should isolate the heater and flush the heat exchanger with an approved descaling solution.
• 4. Check flow NTC sensor: Locate the flow temperature sensor on the outlet pipe or heat exchanger. Inspect for damage and secure contact with the pipe. Replace if readings are erratic or out of specification.
• 5. System circulation (for models with pump): Verify that the internal pump runs and that there are no airlocks. Bleed air from high points if necessary.