What this error means
Overheating fault — water temperature has exceeded a safe limit
The E20 or F20 error means the machine has detected that the water temperature has risen beyond the safe maximum, or that the heating is no longer being controlled correctly. This is a serious fault. It is typically caused by a faulty NTC thermistor providing incorrect temperature readings to the control board, a relay on the control board that has stuck in the closed position, or a failed thermal cutout.
What you'll need first
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Step-by-step
Symptoms to look for
- Machine becomes very hot to the touch on the door glass during a normal or cool wash
- Steam or a hot smell coming from around the door seal during a cycle
- E20 or F20 appears during any programme, including low-temperature washes
- Machine shuts off suddenly mid-cycle with no other explanation
Diagnostic steps
Turn the machine off and unplug it from the mains immediately. Leave the door closed — do not try to open it as the water inside may be scalding. Leave the machine to cool for a minimum of 30 minutes before touching it or attempting any inspection.
After the machine has cooled completely, keep it unplugged and hold the power button for 10 seconds to discharge stored power from the control board. Leave unplugged for a further 60 seconds. Plug back in carefully and try a short cold wash (30 degrees). Monitor it closely for the first 10 minutes.
With the machine fully unplugged, access the heating element via the rear panel (remove the screws around the edge). The NTC thermistor is the small sensor mounted on or near the element. Disconnect its two wires from the control harness and test across the terminals with a multimeter set to resistance. At room temperature it should read 10,000 to 50,000 ohms. A zero or OL reading means the thermistor has failed and is most likely the cause of the uncontrolled heating.
Near the heating element you will also see a small white or silver disc component — the thermal cutout or thermal fuse. This is a one-shot safety device that permanently opens if a critical over-temperature event has occurred. Test it with your multimeter set to continuity — a healthy cutout gives a beep or near-zero reading. No continuity means it has blown and must be replaced.
If the thermistor and thermal cutout both test correctly, the fault likely lies with the control board — specifically a relay that has stuck in the closed position and is supplying continuous power to the heating element. This prevents the control board from switching heating off when the target temperature is reached.
When to call an engineer
- Thermal cutout (thermal fuse) has blown — shows open circuit on continuity test
- NTC thermistor reads zero or open circuit — giving the control board incorrect temperature data
- Control board relay stuck closed — element receives continuous power regardless of temperature
- Burning smell or visible scorch marks near the heating element or control board
Frequently asked questions
Is E20 dangerous?
Can I open the door straight away when E20 appears?
Is E20 caused by selecting too high a temperature?
Can I fix this myself?
🎯 What is likely causing this fault?
⚠️ Estimates based on common faults — not a guaranteed diagnosis. Always verify before ordering parts.
Parts you may need
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Usually found on a label inside the door frame or on the back panel of the machine.
| Part | Approx. UK Cost | Find it |
|---|---|---|
| Heating Element | £15 - £20 | 🏷️ eBay UK → |
| Heating Element | £15 - £20 | 🛒 Amazon UK → |
ℹ️ Prices are approximate. Always check the part number matches your model before ordering. Not sure of your model number? Find out how to locate it here.