Display shows A06, boiler stops, often associated with domestic hot water demand

Safety: Isolate power and close cold water inlet before removing any DHW components. Hot water can scald.

Steps:

• Power cycle: Turn the boiler off and back on to see if the code clears temporarily. Intermittent faults may indicate a loose connection.
• Check sensor wiring: Remove the front panel and locate the DHW NTC sensor on the plate heat exchanger or DHW outlet pipe. Ensure the connector is firmly seated and wires are not damaged.
• Inspect DHW filter and flow sensor: On combi models, check the cold water inlet filter and flow sensor for debris or limescale. Clean the filter screen and gently flush the sensor.
• Temperature reading check: If the control panel shows unrealistic DHW temperatures (e.g., -40°C or 120°C), the NTC sensor is likely faulty and should be replaced.

Professional help: Replacement of NTC sensors or flow switches is straightforward but should be done by a competent person to avoid leaks and ensure correct sealing.