Water Intake Fault
The F12 error code indicates your Miele dishwasher is not receiving enough water. The control board has detected that the tub did not fill to the required level within the allowed time, or the water flow rate is below the expected threshold.
~55%
DIY Fixable
$100-300
Typical Repair Cost
30 min – 1 hr
Pro Repair Time
Quick Assessment
Answer to continue safely
Is it safe to keep using?
No. Running the dishwasher without adequate water can damage the wash pump (running dry) and will not clean dishes properly. Resolve F12 before starting a new cycle.
Can I reset the code?
Yes. Yes. Turn off at mains for 5 minutes. But the reset only clears the display — if the water supply is still restricted, the code will return.
When to stop immediately?
Stop if you notice: The tub does not fill at all after verifying the tap is open, You hear buzzing from the inlet valve but no water enters.
Symptoms You May Notice
Cycle does not start properly
The dishwasher attempts to fill but stops or pauses early in the program
Very little water inside the tub
Opening the door reveals the tub is nearly empty or water barely covers the filters
Wash results are poor
If the machine runs with insufficient water, dishes come out dirty with detergent residue
Clicking sound from the inlet valve
The solenoid valve may click rapidly as it tries to open and close against low pressure
Possible Causes
Water Supply Tap Closed or Partially Closed
The shut-off valve feeding the dishwasher is not fully open, restricting flow. This is the #1 cause (~40% of cases).
DIY PossibleKinked or Blocked Inlet Hose
The braided or rubber inlet hose is bent, crushed, or has sediment buildup inside, reducing water flow.
DIY PossibleClogged Inlet Filter Screen
A small mesh filter sits where the inlet hose connects to the dishwasher. Mineral deposits or debris can block it over time.
DIY PossibleFaulty Inlet Valve (Solenoid)
The electromagnetic valve that controls water entry has failed electrically or is stuck closed.
Requires ProfessionalLow Household Water Pressure
If your home water pressure is below ~0.5 bar (7 psi), the dishwasher may not fill fast enough. This can happen when multiple fixtures run simultaneously.
DIY PossibleSafe Checks You Can Do
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1
Check the Water Supply Tap
Locate the shut-off valve under the sink that feeds the dishwasher. Turn it fully counterclockwise to ensure it is completely open.
After plumbing work or moving the machine, this valve is often left partially closed.
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2
Inspect the Inlet Hose
Pull the machine out carefully. Check the hose from the tap to the machine for kinks, tight bends, or visible damage. Straighten any sharp bends.
The hose should have a gentle curve — no sharp angles within 10 cm of either end.
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3
Clean the Inlet Filter Screen
Turn off the water supply. Unscrew the inlet hose from the back of the dishwasher. You will see a small mesh filter inside the connection. Remove it carefully with pliers, rinse under running water, and refit.
In hard-water areas, soak the filter in white vinegar for 15 minutes to dissolve mineral deposits.
Tools required -
4
Test Household Water Pressure
Run the kitchen tap fully while no other fixtures are in use. If the flow is noticeably weak, the problem may be low mains pressure or a partially closed main valve.
Try running the dishwasher at a time when no other appliances (washing machine, sprinklers) are using water.
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5
Power Reset
Turn off the dishwasher at the mains for 5 minutes. Turn it back on and start a new cycle. Monitor whether the tub fills normally.
If the tub fills but slowly, the issue is restricted flow rather than a valve failure.
When to Call a Professional
Contact a qualified Miele technician if:
- Inlet valve buzzes but no water flows — valve likely failed
- F12 persists after confirming full water supply and clean filter
- Water pressure at the tap is normal but the machine does not fill
- The AquaStop hose indicator shows red (hose has triggered)
- The machine is under warranty
Need Professional Help?
Find qualified Miele technicians in your area for proper diagnostics and repair.
Schedule Appointment