Washing Machine
E66
The E66 error code on an AEG washing machine indicates a fault with the heating element circuit — specifically, the machine has detected that the heater is permanently switched on or is not being controlled correctly. It’s a moderately serious fault that will prevent your machine from completing a cycle safely.
What does this error mean?
The E66 code means the washing machine’s control board has detected an abnormal signal from the heating element or its relay — the component that switches the heater on and off. In plain terms, the machine thinks the heater is stuck in the ‘on’ position or is receiving power when it shouldn’t be. Left unchecked, this could cause overheating, so the machine locks out to protect itself and your laundry.
Est. repair cost
£80–£160 professional repair; £10–£20 DIY NTC sensor replacement if that is the cause
🔍 Likely causes
🛠️ Step-by-step fix
Perform a hard reset first: switch the machine off at the wall socket, wait 10 minutes, then power back on and run a short cycle to see if the error clears. A one-off software glitch can trigger E66.
Check your consumer unit (fuse box) for any tripped breakers associated with the washing machine circuit and reset if needed.
Inspect the area around the machine for signs of overheating — a burning smell, discoloured drum, or very hot casing. If present, do not use the machine and call a professional immediately.
If you are confident working safely with appliances (machine unplugged and isolated), remove the back panel and visually inspect the wiring to the heating element for obvious burns, breaks, or loose connectors. Reconnect any loose terminals carefully.
Test or replace the NTC temperature sensor — this is a low-cost part (£10–£20) and a relatively straightforward DIY replacement with the machine unplugged. Search your model number on a UK spares site such as eSpares or 4ourhouse.
If the wiring looks intact and a sensor swap doesn’t resolve the fault, stop DIY work. The heating element itself or the PCB relay will need professional diagnosis — opening or bypassing the control board is not a safe DIY task.
📞 When to call a professional
Call a qualified appliance engineer if the error persists after a reset, if you detect any burning smell or scorch marks, or if basic wiring checks don’t reveal an obvious fix. When you call, tell the engineer: ‘My AEG washing machine is showing error code E66 — it’s a heater relay or heating element circuit fault.’ This saves diagnostic time and may reduce your call-out cost.
⚖️ Repair or replace?
A professional repair for E66 typically costs £80–£160 depending on whether it’s a sensor, element, or PCB relay replacement. If your AEG machine is under 5 years old, repair is almost always the right call. If it’s over 8–10 years old and the PCB needs replacing (parts alone can be £80–£120+), weigh this against a new mid-range AEG washing machine at £400–£600 — replacement may be more economical in the long run.