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Error code reference

Miele Dishwasher Error Code F12

Water intake fault at start of step; during the first 5 seconds of any water intake step, at least 15 pulses…

Miele codesMiele dishwasher codes

Water intake fault at start of step; during the first 5 seconds of any water intake step, at least 15 pulses from flow meter B3-4 were not registered.

First step from the service manual

Check that the on-site shutoff valve (water supply) is open.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What F12 means on a Miele dishwasher

The F12 error code on a Miele dishwasher indicates a water intake fault detected at the very beginning of a fill cycle. Specifically, the control board expects to register at least 15 pulses from the flow meter (component B3-4) within the first 5 seconds of any water intake step. If those pulses are not detected, the machine concludes that water is not entering the unit at an adequate rate and halts the program to prevent damage. This is a time-critical check: the 5-second window means the fault is caught early, before a prolonged fill attempt could mask a more serious supply problem.

The flow meter B3-4 is a turbine-based sensor positioned in the water inlet path. As water flows through, the turbine spins and generates electrical pulses that the control board counts to measure flow rate and volume. A reading of zero or fewer than 15 pulses in 5 seconds tells the board that flow is either completely absent or severely restricted. The most straightforward cause is a closed or partially closed shutoff valve at the water supply connection, which is why verifying that valve is fully open is the first diagnostic step.

Beyond the supply valve, the fault can originate from a kinked or pinched inlet hose, a clogged inlet valve filter screen, a failed water inlet solenoid valve, or a defective flow meter sensor itself. In some cases, low incoming water pressure from the household supply can also prevent sufficient flow from registering within the required window. Diagnosing the root cause involves working through the water supply path systematically, from the shutoff valve through the inlet hose, inlet valve, and finally the flow meter and its wiring.

Source: manufacturer service documentation.

Common causes of F12

  1. 01

    Closed or partially open shutoff valve

    Wiring / connection

    The water supply valve under the sink or behind the dishwasher may be fully or partially closed, preventing water from entering. Open the valve completely and restart the cycle to see if the error clears.

  2. 02

    Kinked or pinched inlet hose

    Wiring / connection

    The water inlet hose connecting the supply valve to the dishwasher may be bent or pinched, restricting flow. Inspect the full length of the hose and straighten any kinks.

  3. 03

    Clogged inlet valve filter screen

    Wiring / connection

    A mesh filter screen inside the water inlet valve fitting can accumulate mineral deposits and debris over time, severely restricting flow. The screen can usually be removed and cleaned with a small brush and vinegar solution.

  4. 04

    Failed water inlet solenoid valve

    Part replacement

    The electrically operated inlet valve may have failed mechanically or electrically and is not opening when the control board signals it to. If water supply and hose are confirmed good, the inlet valve likely needs replacement.

  5. 05

    Defective flow meter (B3-4)

    Part replacement

    If water is confirmed to be entering the machine but F12 still appears, the flow meter sensor B3-4 may be faulty or have a wiring issue, causing it to not generate or transmit pulses to the control board. Inspect the wiring connections to B3-4 and test or replace the sensor.

See the test procedure for each cause

Frequently asked questions about F12

What does F12 mean on a Miele dishwasher?
F12 is a water intake fault that appears when the dishwasher's flow meter does not register at least 15 pulses within the first 5 seconds of a water intake step. This tells the control board that water is not flowing into the machine at the required rate. The machine stops the cycle to prevent running without adequate water. The most common cause is a closed water supply shutoff valve.
How do I fix an F12 error on my Miele dishwasher?
Start by confirming the water supply shutoff valve is fully open and that the inlet hose is not kinked or pinched. Next, check the filter screen inside the inlet valve fitting for clogs and clean it if needed. If those steps do not resolve the error, the water inlet solenoid valve or the flow meter sensor B3-4 may need to be tested and replaced by a qualified technician.
Will resetting my Miele dishwasher clear the F12 error?
Resetting the dishwasher may clear the displayed error temporarily, but the fault will return as soon as the machine attempts another fill cycle if the underlying problem has not been fixed. A reset is only useful to confirm whether the issue is resolved after you have addressed the root cause. The F12 condition is based on real-time flow meter readings, so the control board will detect the fault again immediately if water flow is still inadequate.
Is it safe to continue using my Miele dishwasher when F12 appears?
You should not attempt to run a wash cycle while F12 is active. The dishwasher has halted the program precisely because water is not entering correctly, and running the machine without adequate water supply can stress the pump and heating element. Address the water supply issue before restarting the appliance.
How much does it cost to repair a Miele dishwasher F12 error?
If the fix is simply opening the shutoff valve or straightening a kinked hose, there is no parts cost involved. Cleaning a clogged inlet valve screen is also typically a no-cost repair. If the water inlet solenoid valve needs replacement, parts and labor can range from roughly 100 to 250 dollars depending on your location and service provider. Replacing the flow meter sensor B3-4 can carry a similar or somewhat higher cost given the complexity of accessing the component.

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