Turbidity Sensor Fault
The F87 error code means the turbidity sensor (water clarity sensor) in your Miele dishwasher is not functioning correctly. This optical sensor measures how dirty the wash water is — when it fails, the machine cannot optimize cycle length or determine when water needs to be changed during the program.
~50%
DIY Fixable
$100-300
Typical Repair Cost
20 min – 1 hr
Pro Repair Time
Quick Assessment
Answer to continue safely
Is it safe to keep using?
Yes. F87 does not prevent the dishwasher from washing or sanitizing. The machine will default to maximum cycle times, which means it will still clean effectively — just less efficiently. Safe to use while troubleshooting.
Can I reset the code?
Yes. Yes. Turn off at mains for 5 minutes. A cleaning cycle followed by a reset often resolves F87 if the cause was a dirty sensor lens.
When to stop immediately?
Stop if you notice: F87 persists after cleaning, descaling, and resetting, The machine's water consumption has noticeably increased.
Symptoms You May Notice
Cycles run longer than necessary
Without turbidity data, the machine defaults to maximum wash times as a precaution
Water changes more or less frequently than normal
The board may drain and refill extra times or skip changes it should make
Dishes sometimes come out less clean
If the sensor reports clean water when it is still dirty, the machine may end the wash phase too early
Higher water and energy consumption
Default-to-maximum behavior uses more water and energy than sensor-optimized cycles
Possible Causes
Dirty Sensor Lens
Grease, limescale, or food film has coated the optical sensor window, blocking the light beam. This is the most common cause (~50%).
DIY PossibleFailed LED or Photodiode
The light source or the light detector in the sensor has burned out.
Requires ProfessionalWiring or Connector Issue
A loose or corroded connection between the sensor and the control board interrupts the signal.
Requires ProfessionalSensor Positioning
The sensor has shifted from its mounting position due to vibration, giving incorrect readings.
Requires ProfessionalControl Board Input Fault
The analog-to-digital converter on the board that reads the sensor output has failed.
Requires ProfessionalSafe Checks You Can Do
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1
Run a Hot Cleaning Cycle
Run the hottest cycle empty with a dishwasher cleaner or 2 cups of white vinegar. This dissolves grease and limescale on the sensor lens.
Repeat monthly in heavy-use households to keep the sensor clean.
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2
Clean the Filters Thoroughly
Dirty filters allow particles to recirculate and coat the sensor. Remove and scrub all filters under running water.
A clean filter system is the best prevention for turbidity sensor issues.
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3
Run a Descaling Cycle
Use Miele descaling tablets to remove mineral deposits. Limescale on the sensor window is a common cause in hard-water areas.
Alternate between cleaning and descaling cycles for the best results.
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4
Power Reset
Turn off at mains for 5 minutes. The sensor may need to recalibrate after cleaning.
After the reset, run a normal cycle and check if cycle times return to normal.
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5
Monitor Cycle Times
Compare cycle times after cleaning with the expected times in your manual. If they normalize, the sensor was simply dirty.
If cycle times stay at maximum despite cleaning, the sensor itself may have failed.
When to Call a Professional
Contact a qualified Miele technician if:
- F87 persists after thorough cleaning and descaling
- Cycle times remain at maximum despite a clean sensor area
- The sensor LED is visibly not illuminating (requires opening the machine)
- F87 + other sensor codes appear — possible board-level issue
- The machine is under warranty
Need Professional Help?
Find qualified Miele technicians in your area for proper diagnostics and repair.
Schedule Appointment