Washer displays E12; often associated with heating problems and limescale build-up.

Safety: Unplug the washer before inspection.

• Run a maintenance wash: With the drum empty, run a 90 °C cotton cycle using a proprietary descaling product suitable for washing machines. This can reduce limescale on the heater and tub.
• Check detergent use: Ensure you are using HE (high-efficiency) detergent in the correct quantity for your water hardness. Overdosing can cause residue and poor heating performance.
• Inspect heater: If E12 persists, remove the rear panel and inspect the heater. Remove it if necessary to check for heavy scale build-up. Replace the heater if it is badly encrusted or pitted.
• Preventive care: In hard water areas, use a water softener or regular descaling cycles to prevent recurrence.