Battery will not charge; charger LED blinks red or shows E4 on a display dock; vacuum remains unresponsive.

Safety first: Unplug the charger from the mains before inspecting contacts. Do not attempt to open the charger or battery pack.

• Verify mains outlet: Plug another device into the same outlet to confirm it has power. Try a different outlet if needed.
• Inspect charger and cable: Check for cuts, kinks, or burn marks on the cable and plug. If damaged, stop using it immediately and replace with an original Zanussi charger.
• Clean charging contacts: On the battery and charging dock/handle, gently wipe the metal contacts with a dry cloth. Ensure there is no corrosion or debris.
• Check battery seating: Make sure the battery clicks firmly into the dock or handle. A loose fit can prevent charging.
• Test with another battery or charger (if available): Swap components to isolate whether the fault is in the charger, battery, or vacuum body.

If E4 persists with a known‑good charger and outlet, the battery pack or internal charge circuitry is likely defective. Replace the battery pack first; if the issue remains, the main control PCB in the handle may require professional replacement.