What Does This Error Mean?

A Dolphin cleaner that moves but leaves debris behind usually has a full filter bag or cartridge reducing suction. Empty and rinse the filter after every 2–3 cycles. Worn brushes that no longer sweep debris toward the suction opening are also a common cause.

Affected Models

Dolphin Nautilus CC
Dolphin Nautilus CC Plus
Dolphin E10
Dolphin E20
Dolphin Sigma
Dolphin S300i

Common Causes

Filter bag or cartridge full — suction drops significantly
Worn or flattened brush bristles not directing debris into the suction port
Suction port blocked by a single large piece of debris
Debris too fine for the installed filter (requires ultra-fine filter cartridge)
Cleaner moving too fast for heavy debris — try a slower speed setting

How to Fix It

Empty and rinse the filter bag or cartridge.

Remove the filter basket from the top of the cleaner. Shake out debris over a bin, then rinse thoroughly with a garden hose. For fine debris pools, use an ultra-fine mesh filter cartridge which traps smaller particles than the standard bag.
Inspect the brushes.

Turn the cleaner over and examine the brush rolls. Bristles should stand upright and feel firm — if they are flattened, frayed, or worn down, they can no longer sweep debris toward the intake. Brushes are wear items and typically last 1–2 seasons.
Check the suction port for blockages.

With the cleaner out of water, look into the suction inlet at the base. A single large leaf or object can partially block the opening and drastically reduce pickup. Remove any visible blockage.
Run a manual spot-clean cycle.

Some Dolphin Wi-Fi models allow manual steering via the app. Drive the cleaner directly over debris concentrations to confirm suction is working. If suction feels strong in manual mode, the navigation algorithm may be missing spots — try a longer cycle.
Match the filter type to your debris type.

Standard mesh filters catch large debris (leaves, acorns) but allow fine dust through. Ultra-fine cartridge filters are required for sand, silt, or fine organic matter. Check Maytronics' filter compatibility guide for your Dolphin model.

When to Call a Professional

If debris pickup remains poor after filter cleaning and brush replacement, the impeller motor may be underperforming. Contact Maytronics support for a motor efficiency test.