Washer High Severity
F20 Miele Error Code

Heating Fault

The F20 error code means the heating element in your Miele washing machine is not raising the water temperature to the level required by the selected program. The control board has detected that the target temperature was not reached within the allowed heating time.

~20%

DIY Fixable

$200-450

Typical Repair Cost

1-2 hrs

Pro Repair Time

Quick Assessment

Answer to continue safely

Is it safe to keep using?

Maybe. You can use cold-water programs safely. But hot-water programs will not clean effectively without heating. If F20 persists, the heater needs professional attention.

Can I reset the code?

Yes. Yes. Turn off at mains for 5 minutes. If caused by a temporary sensor glitch, the reset may clear it. If the heater has failed, F20 will return.

When to stop immediately?

Stop if you notice: The machine trips the household breaker, You smell burning from the machine.

Symptoms You May Notice

Clothes come out cold

Laundry feels cold after a hot-wash cycle

Cycle runs much longer than expected

The machine extends the heating phase, trying to reach temperature before timing out

Stains are not removed

Hot-water cycles are needed for protein stains, grease, and sanitization — cold water is ineffective

F20 appears mid-cycle

The code triggers during the wash phase when heating should be active

Possible Causes

1

Failed Heating Element

The heater has burned out or developed an open circuit. Most common cause (~50%).

Requires Professional
2

Defective NTC Temperature Sensor

The sensor gives incorrect readings, preventing proper heater control.

Requires Professional
3

Limescale on the Heater

Heavy mineral deposits insulate the element, reducing heating efficiency.

DIY Possible
4

Wiring Fault

A loose connector or broken wire between the heater and the control board.

Requires Professional
5

Control Board Relay Failure

The relay that switches power to the heater has failed.

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 at mains for 5 minutes. Run a 60°C cotton cycle and check if the door glass feels warm after 20 minutes.

    The door glass is a quick way to verify heating — it should be noticeably warm during a hot cycle.

  2. 2

    Run a Descaling Cycle

    Use Miele descaling tablets. Run a 95°C maintenance wash with an empty drum.

    Descale every 3-4 months in hard-water areas.

  3. 3

    Try a Cold Cycle

    Run a cold-water cycle to verify the machine works otherwise. If it completes normally, the issue is isolated to the heating system.

    Cold cycles do not trigger the heater — useful for isolating the fault.

  4. 4

    Check for Tripped Breaker

    If the heater has a short circuit, it may trip the household breaker. Check your breaker panel.

    A heater that trips the breaker needs replacement — do not reset and retry.

  5. 5

    Note All Codes

    Check if F20 appears alone or with other codes (F29, F43). Multiple codes help a technician diagnose faster.

    Write down all codes in order.

When to Call a Professional

Contact a qualified Miele technician if:

  • No heating at all after 30 minutes
  • Machine trips the breaker during heating
  • F20 appears with F29 or F43
  • Burning smell from the heater area
  • Under warranty

Need Professional Help?

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

Schedule Appointment

More Washer Error Codes

View all codes →
F138 F103 F62 F56 F53 F50 F46 F43 F35 F34 F29 F19