Washing Machine
E91
The E91 error code on an AEG washing machine signals a communication fault between the main control board and the user interface (display panel). It’s a moderately serious fault — the machine will typically stop working until it’s resolved.
What does this error mean?
E91 means the main PCB (printed circuit board) and the front display/control panel have lost communication with each other. The machine’s two ‘brains’ are no longer talking, so it cannot safely accept commands or run a programme. This is usually an electrical connection issue rather than a full board failure, which means it’s often fixable without expensive parts.
Est. repair cost
£80–£180 professional repair; £20–£60 DIY if only a connector or ribbon cable needs replacing
🔍 Likely causes
🛠️ Step-by-step fix
Power cycle the machine: switch it off at the wall socket, wait 5 minutes, then switch it back on and attempt to start a new programme. This clears temporary communication errors and costs nothing.
Check the door is fully closed and the drum is not overloaded — some AEG models trigger secondary errors that display as E91 when another fault prevents startup.
Inspect the detergent drawer and surrounding area for moisture or detergent residue that may have tracked down to the wiring below. Clean and dry the area thoroughly.
If you’re comfortable doing so safely: disconnect the machine from the mains, remove the top panel (usually two screws at the rear), and locate the wiring harness that runs from the main board to the control panel. Press each connector firmly to reseat it. Do not open or probe the PCB itself.
Reconnect the power and test. If E91 returns immediately and consistently after a full power cycle, the fault is unlikely to be a loose connection — stop DIY here.
Do not attempt to replace the PCB or UI board yourself unless you have appliance repair experience — incorrect installation can cause further damage or electrical risk.
📞 When to call a professional
Call an appliance engineer if the E91 error returns immediately after a power cycle, or if reseating the harness connectors makes no difference. Tell them it’s an AEG E91 fault — a communication error between the main PCB and user interface board — so they can bring the likely parts. Look for an engineer registered with the Domestic Appliance Service Association (DASA) or a Which? Trusted Trader.
⚖️ Repair or replace?
A professional repair for E91 typically costs £80–£180 depending on whether the fault is a wiring issue (cheaper) or a PCB/UI board replacement (more expensive). If your AEG washing machine is under 5 years old, repair is almost always the right call. Over 8 years old with a PCB fault, weigh the repair cost against a new machine — AEG mid-range models start around £450–£600.