Cordless vacuum will not charge, charger LED blinks or vacuum LED flashes four times when placed on charger

Safety first: Disconnect the charger from the wall before handling the battery. Do not attempt to cool or heat the battery rapidly (no freezer, oven, or direct sunlight).

• Step 1 – Allow to normalize: If the vacuum was just used heavily, remove the battery (if removable) and let it sit at room temperature (18–25°C / 65–77°F) for at least 30–60 minutes.
• Step 2 – Check environment: Move the charger and vacuum to a dry, indoor location away from direct heat sources or cold drafts. Charging in garages or sheds can trigger temperature errors.
• Step 3 – Inspect battery housing: Look for swelling, cracks, or discoloration on the Dirt Devil battery pack. If any are present, discontinue use immediately and recycle the battery according to local regulations.
• Step 4 – Retry charging: Plug the charger into a known-good outlet, then place the battery or vacuum on the charger. Observe the LED pattern. If E4 persists at normal room temperature, the internal NTC sensor or battery PCB is likely faulty.
• Step 5 – Replace battery: Replace the battery pack with a genuine Dirt Devil replacement specified for your cordless model.
• When to stop: If a new battery still shows E4, the charger or main control board may be misreading temperature; contact service.