Single slow red flash on the handle LED when trigger is pulled; motor does not start.

Safety first: Disconnect the battery from the vacuum and unplug the charger from the mains before inspecting contacts. Never short the battery terminals.

Steps to try:

• Check battery charge: Remove the Gtech battery pack and press its charge indicator button (if present). If no LEDs light, the pack may be deeply discharged.
• Attempt a full recharge: Seat the battery firmly into the original Gtech charger. Ensure the charger LED comes on and leave it for at least 4–5 hours. Do not use third‑party chargers.
• Inspect and clean contacts: With the charger unplugged, inspect the metal contacts on the battery and on the vacuum handle. Clean gently with a dry cloth or a pencil eraser. Do not use liquids.
• Test again: Refit the battery until it clicks. Pull the trigger. If the single red flash persists and the motor never starts after a full charge, the battery pack is likely failing internally.
• When to replace: If the pack is more than 2–3 years old or has been stored fully discharged, replace it with a genuine Gtech replacement battery pack.