Dishwasher Medium Severity
F85 Miele Error Code

NTC Temperature Sensor Failure

The F85 error code means the NTC (Negative Temperature Coefficient) temperature sensor in your Miele dishwasher has sent a signal outside the expected range. The control board cannot accurately measure water temperature, so it halts the heating process as a safety precaution.

~20%

DIY Fixable

$150-350

Typical Repair Cost

45 min – 1.5 hrs

Pro Repair Time

Quick Assessment

Answer to continue safely

Is it safe to keep using?

Maybe. You can try one cycle after a reset and descale. If the dishwasher heats normally and completes without error, the issue may have been limescale. If F85 returns, stop — the sensor needs replacement.

Can I reset the code?

Yes. Yes. Turn off at mains for 10 minutes. If the code was a transient glitch, it may not return. If F85 reappears within 1–2 cycles, the sensor has failed.

When to stop immediately?

Stop if you notice: F85 returns after a reset and descaling, The dishwasher no longer heats water at all.

Symptoms You May Notice

Water does not heat

The control board disables the heater when it cannot verify the temperature, so water stays cold

Cycle stops during the wash phase

The machine pauses mid-cycle when the heating phase cannot be completed safely

Dishes come out cold and poorly cleaned

Without hot water, grease remains on dishes and detergent does not dissolve fully

F85 may alternate with F84

The control board may show F84 (general heating fault) on some cycles and F85 (sensor fault) on others

Possible Causes

1

Failed NTC Sensor

The thermistor element has drifted out of calibration or developed an open/short circuit. This is the most common cause (~55% of cases).

Requires Professional
2

Corroded or Loose Sensor Connector

The wiring plug connecting the NTC sensor to the control board has corroded or come loose due to heat and moisture.

Requires Professional
3

Damaged Wiring

The wire harness between the sensor and the board has been damaged by heat, abrasion, or rodent activity.

Requires Professional
4

Limescale Coating on the Sensor

Heavy mineral deposits insulate the sensor from the water, causing delayed or inaccurate readings.

DIY Possible
5

Control Board Fault

The input circuit on the main PCB that reads the sensor signal has failed. Uncommon but possible on older machines.

Requires Professional

Safe Checks You Can Do

These checks are safe for homeowners. No disassembly required. Do not remove panels or access internal components.
  1. 1

    Power Reset

    Turn off the dishwasher at the mains for 10 minutes. Turn it back on and start a normal cycle. If F85 was caused by a momentary electrical glitch, the reset will clear it.

    A 10-minute reset (longer than usual) gives the sensor and board time to fully discharge.

  2. 2

    Run a Descaling Cycle

    Use Miele descaling tablets or citric acid descaler. Run the hottest empty cycle. Limescale coating on the NTC sensor can cause false readings.

    In hard-water areas, a coated sensor is a surprisingly common cause of F85.

  3. 3

    Check for Multiple Error Codes

    Note whether F85 appears alone or with other codes (F84, F14). If multiple heating codes appear, the root cause may be the heater circuit rather than the sensor alone.

    Write down every code you see — a technician can use this to diagnose much faster.

  4. 4

    Monitor the Water Temperature

    Start a cycle and after 15–20 minutes, carefully open the door slightly. If steam escapes and the water feels hot, the heater works and the sensor may be giving a false alarm.

    Be cautious — water can be up to 75°C during the rinse phase.

  5. 5

    Check for Moisture in the Base

    If the machine has had a minor leak, moisture inside the base can affect wiring connections. Check for dampness around the base and underneath.

    Moisture on connectors is a hidden cause of intermittent sensor faults.

When to Call a Professional

Contact a qualified Miele technician if:

  • F85 persists after descaling and multiple resets
  • The NTC sensor reads open circuit or short circuit (technician test)
  • F85 + F84 appear together, indicating a broader heating fault
  • The sensor connector shows visible corrosion
  • The machine is under warranty — sensor replacement is covered

Need Professional Help?

Find qualified Miele technicians in your area for proper diagnostics and repair.

Schedule Appointment

More Dishwasher Error Codes

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F87 F86 F67 F63 F53 F69 F52 F78 F51 F68 F47 F40