Miele Dishwasher Sensor Replacement

Which Sensor, Which Code#

What Each Sensor Does#

The NTC thermistor sits in the water path by the flow-through heater and reports temperature in real time — it is what holds the IntenseClean program at 167°F and keeps standard cycles precise. The turbidity sensor uses an infrared LED and photodiode to read how cloudy the wash water is, letting the Automatic program decide when the dishes are clean enough to rinse. The WPS float switch lives in the base pan: if water pools there from any leak, the float rises and triggers an emergency shutdown with F70. The flow meter counts the water entering from the supply valve so the board knows when each fill is complete.

A Useful Diagnostic Clue#

If the dishwasher cleans poorly on the Automatic program but fine on a manual one, suspect a sensor. Automatic leans on turbidity and temperature feedback, while manual programs run fixed settings — so a failure that only shows on Auto points squarely at the sensing chain rather than the pump or spray arms.

Replacing the Sensors#

The NTC is the easy one: cut power, remove the base cover with a Torx Plus T20, unclip the small cylindrical probe from the water path near the heater, unplug its two-wire connector, and fit the new probe so its tip contacts the water. The turbidity sensor is moderate — pull the machine forward, remove the base cover, release it from the sump return path, and clean the mounting area so no residue clouds the new optical window. The WPS float switch often just needs freeing: check whether the float moves freely, and clean it before replacing, since mineral deposits can jam it up. The flow meter unclips inline on the supply path — close the water, catch the drips, and mind the flow-direction arrow when fitting the new one.

OEM Only#

No aftermarket sensors are made for Miele dishwashers, so all four come from Miele. The upside is that sensors are among the cheapest Miele parts, which makes them sound repairs even on an older machine. Specifications shift by generation, though: G 4000 and 5000 machines use analog NTC and mechanical float parts, while G 7000 and 7900 machines use digital-output NTC and an enhanced turbidity sensor with a wider range. Order by full model and serial number so the turbidity sensor in particular matches.

Why Sensors Matter on a Miele#

Because Miele's automatic programs adjust temperature, cycle length, dosing, and rinse intensity from live readings rather than fixed timers, a single failed sensor either pushes the board into wasteful maximum-resource defaults or stops the cycle outright with a code. That is also why the WPS float is worth understanding: an F70 with no water on the floor is usually a stuck float, not a real flood, and cleaning it clears the shutdown without a part. Treating that code as a plumbing check first, rather than a parts order, saves most owners an unnecessary sensor.