Machine shows F4 and stops brewing; may abort shortly after starting

Safety first: Disconnect power before removing panels. Water and electricity are a dangerous combination.

User-level actions:

• Remove and refill the water tank, ensuring it is fully seated.
• Run the hot water function (if available) to purge air from the system.
• Descale the machine using Miele descaling tablets to clear minor blockages.

Technical steps:

• Access the internal water circuit and locate the flow meter (usually a small round plastic component in-line between the water tank and pump).
• Check for kinks or blockages in the silicone hoses connected to the flow meter.
• Disconnect the hoses and gently blow through the flow meter; it should allow air to pass and you may hear the internal wheel spin.
• Inspect and reseat the electrical connector to the flow meter; check for corrosion or broken wires.
• Use a multimeter or oscilloscope (if available) to verify that the flow meter outputs pulses when water flows (refer to Miele service data).

Resolution:

• If the flow meter is mechanically stuck or electrically dead, replace it with the correct Miele flow meter for your model.
• If the flow meter is good but F4 persists, the control board input may be faulty and require professional replacement.