Washing Machine Medium Severity
F86/Miele Error Code

Heating Element / Temperature Control Fault

The F86 error code indicates that your Miele washing machine's control system has detected a problem with the heating circuit or temperature sensor. The water is not reaching the required temperature for effective operation.

~45%

DIY Fixable

$150-400

Typical Repair Cost

1-2 hrs

Pro Repair Time

Quick Assessment

Answer to continue safely

Is it safe to keep using?

Maybe. You can run 1-2 more cycles to see if the error clears. If it persists, stop using — items won't be properly sanitized.

Can I reset the code?

Yes. Turn off at mains for 5 minutes. If code returns within 1-2 cycles, the fault is real.

When to stop immediately?

Stop if you notice: if you notice burning smell, if error persists after 3 resets.

Symptoms You May Notice

Cycle stops mid-way

Appliance halts during wash or operation phase

Items remain cold

Water not heating to proper temperature

Poor cleaning results

Cold water can't dissolve fats effectively

Extended cycle times

Machine trying longer to reach temperature

Possible Causes

1

Faulty Heating Element

The heating element has failed or developed a fault. This is the most common cause (~40% of cases).

Requires Professional
2

Defective NTC Temperature Sensor

The temperature sensor provides incorrect readings to the control board, even if the heater works.

Requires Professional
3

Limescale Buildup

Heavy limescale deposits on the heating element reduce efficiency and can trigger temperature faults.

DIY Possible
4

Wiring or Connection Issues

Loose connections or damaged wiring to the heating circuit can interrupt power supply.

Requires Professional
5

Control Board Malfunction

The main PCB may have failed components affecting temperature regulation. Less common but possible.

Requires Professional

Safe Checks You Can Do

These checks are safe for homeowners. No tools or disassembly required. Do NOT remove any panels or access internal components.

  1. 1

    Power Reset

    Turn off the appliance at the mains (not just the button). Wait 5 full minutes. Turn back on and run a short cycle.

    This clears temporary glitches in ~15% of cases

  2. 2

    Check Hot Water Supply

    Run the hot water tap at your kitchen sink for 30 seconds before starting. This ensures hot water reaches the machine immediately.

    Helps if your water heater is far from the appliance

  3. 3

    Clean the Filters

    Remove and clean the main filter and fine mesh filter. Blocked filters can affect water circulation and heating efficiency.

    Should be done monthly anyway

  4. 4

    Run a Descaling Cycle

    Use Miele descaling tablets or a quality descaler. Run the hottest cycle empty. Limescale on the heater is a common cause.

    Especially important in hard water areas

  5. 5

    Check Inlet Water Temperature

    If connected to cold water only, ensure the machine isn't expecting pre-heated water. Check your manual for water connection requirements.

    Some models require hot water connection

When to Call a Professional

Contact a certified Miele technician if:

  • Error returns after power reset and descaling
  • You notice any burning smell from the machine
  • F86 appears together with F85, F70, or F24
  • The appliance is under warranty (don't void it!)
  • You hear unusual sounds during heating phase

Need Professional Help?

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

Find Service Near Me

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