Cordless vacuum will not switch on, display briefly lights then shuts off with F1

Safety first: Switch the vacuum OFF, remove the battery pack from the handle, and disconnect the charger from the mains before working on the unit.

• 1. Reseat the battery pack: Remove the battery from the handle, inspect the rails and locking tabs for debris or damage, then firmly slide the battery back in until it clicks. Try powering on again.
• 2. Inspect battery contacts: Look at the metal contacts on the battery pack and inside the handle. If you see light oxidation, clean gently with a dry microfiber cloth. Do not use liquids. If contacts are heavily pitted or burned, the battery pack may need replacement.
• 3. Test with another battery (if available): If you have a second Miele battery compatible with your model (e.g. Triflex HX1/HX2 pack), insert it and test. If F1 disappears, the original battery pack is faulty.
• 4. Check for play in the handle connection: Wiggle the battery slightly when installed. Excessive movement can interrupt communication. If the housing is cracked or the latch is worn, the handle or battery casing may need replacement.
• 5. If F1 persists: The battery management PCB or the main control PCB may be defective. Do not attempt to open the battery pack. Contact a Miele service technician for battery or handle PCB replacement.