Miele Dishwasher Error Code F18 — Flow Meter Fault
What this means
Error F18 specifically indicates a failure of the flow meter (turbine sensor) inside the water inlet valve assembly. Unlike F12/F13 which may be caused by low water pressure, F18 points directly to the flow meter hardware. The control board receives no pulse signal from the meter even though the inlet valve is open. This is typically caused by a seized turbine due to limescale, a failed Hall-effect sensor in the meter, or a broken wire between the flow meter and the control board.
Alternate codes: F 18
Step-by-step fix
4 stepsConfirm water is flowing
Disconnect the inlet hose at the dishwasher end (with the tap turned off first). Hold the hose over a bucket, turn on the tap, and confirm strong water flow. This rules out a supply issue.
If flow is weak, the issue is upstream of the dishwasher and F18 is a secondary symptom.
Inspect the flow meter turbine
Access the inlet valve assembly at the bottom of the dishwasher. The flow meter is usually a small cylindrical component attached to or built into the valve body. If accessible, check that the turbine inside spins freely by blowing air through it or gently pushing it with a toothpick.
Soaking the flow meter in white vinegar for 30 minutes can dissolve minor limescale deposits and restore function.
Check the flow meter wiring
Trace the wiring harness from the flow meter to the control board connector. Look for pinched, chafed, or disconnected wires. Reseat the connector at the control board end.
Miele flow meters typically have 2 or 3 thin wires. A broken connection on any one of them will cause F18.
Replace the inlet valve assembly
If the turbine is seized or the Hall-effect sensor has failed, the entire inlet valve/flow meter assembly typically needs to be replaced as a unit. Disconnect the water line, remove the electrical connector, unscrew the mounting, and install the new assembly.
Miele often integrates the flow meter into the inlet valve body — they are not sold separately.
When to call a professional
If the flow meter wiring and valve are fine but F18 persists, the control board input circuit may be damaged, which requires professional board-level diagnosis.
Related error codes
Information compiled from manufacturer service manuals, official troubleshooting documentation, and appliance repair industry resources. This guide is for informational purposes only — always consult a qualified technician for complex repairs.
Learn more about our sourcesParts you may need
Water Inlet Valve with Flow Meter
Part #7638580 · $50–$100
If turbine is seized or sensor has failed
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