Dishwasher shows E12; salt or water softener system issues, poor washing with limescale deposits

Safety first: Switch off power before removing lower panels; avoid spilling salt into the tub.

• Check salt level: Open the salt reservoir cap in the bottom of the tub and ensure it is filled with dishwasher salt (not table salt). Top up if low and wipe away any spilled salt.
• Run regeneration: Many models automatically regenerate; run a full cycle after refilling salt to allow the system to reset.
• Inspect softener valve: Access the softener valve (usually near the side water matrix or softener tank). Check the coil for correct resistance with a multimeter. Replace if open-circuit.
• Check for blockages: Inspect hoses to and from the softener tank for kinks or blockages. Clear any obstructions.
• Monitor results: If E12 persists and limescale continues to form, the softener assembly or control board may require professional diagnosis and replacement.