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Home › Why Is My Dolphin Pool Cleaner Not Climbing Walls? (7 Fixes)

By Shaz · Updated September 2026

Why Is My Dolphin Pool Cleaner Not Climbing Walls?

If your Dolphin cleans the floor perfectly but won't climb the walls or reach the waterline, don't panic — it's rarely a serious fault. In almost every case it's caused by reduced suction, worn traction or slippery walls, and it's fixable in a few minutes with no tools. Here are the seven most common causes and exactly how to fix each one. Quick checklist (in order): clean the filter → clear the brushes → release trapped air → check the impeller → inspect the tracks → brush algae off the walls → confirm the cleaning mode. Most wall-climbing problems are solved by the first two.

1. The Filter Is Full or Dirty

This is the number-one cause. A clogged filter chokes the suction the cleaner relies on to grip and climb vertical surfaces. If it's cleaning the floor but losing power on the walls, start here. Fix: Remove the filter basket or cartridges, empty them, and rinse thoroughly with a hose until the water runs clear. Refit securely. Clean the filter after every cycle to keep suction at full strength.

2. Tangled or Worn Brushes

Hair, fibres and debris wrap around the brush axles and stop the brushes gripping. Worn-flat brushes lose the traction needed to climb. Fix: Turn the unit over and pull away any tangled hair or fibres. If the brushes are worn smooth or frayed, replace them — worn brushes are one of the most common reasons a cleaner stops climbing.

3. Trapped Air in the Unit

If air is trapped inside the cleaner, it becomes buoyant and can't press itself against the walls to climb. Fix: Before each cycle, lower the cleaner into the water at an angle and let the air bubbles escape until it sinks properly. Don't just drop it in flat — let it fully submerge and settle first.

4. Blocked Impeller

The impeller generates the suction. If hair, twigs or small debris are caught in it, suction drops and the cleaner can't hold the walls. Fix: Following your model's manual, check the impeller opening and gently remove any lodged debris. Never force objects into the housing.

5. Worn Tracks or Debris in the Tracks

The rubber tracks provide the grip that lets the cleaner drive up walls. If they're worn, loose or jammed with debris, traction fails. Fix: Inspect the tracks for wear and clear anything caught in them. Replace tracks or belts that are stretched or worn.

6. Slippery Walls (Algae or Water Chemistry)

Sometimes the cleaner is fine — the walls are the problem. A thin layer of algae or biofilm makes surfaces slick, and the cleaner slides back down. Fix: Brush the walls manually and correct your water chemistry (balance sanitiser and pH). Once the algae film is removed, grip usually returns immediately. Tip: Very smooth surfaces like polished tile are naturally harder to climb than concrete or plaster. If your pool is fully tiled, some reduction in climbing traction is normal.

7. The Wrong Cleaning Mode Is Selected

On models with multiple programs (or app control), a floor-only mode may be active — so the cleaner is behaving exactly as set. Fix: Check the selected cycle in the MyDolphin Plus app or on the power supply and switch to a mode that includes walls and waterline.

Still Not Climbing? When to Contact Support

If you've worked through all seven and the cleaner still won't climb, the issue may be a motor or power-supply fault. Note your model number and the exact behaviour, then contact your dealer or Maytronics support — if the unit is within warranty, don't attempt internal repairs, as that can void it. Prevent most of these problems in the first place with our guide on how to maintain a Dolphin robotic pool cleaner. Need replacement brushes, tracks or filters? Browse Dolphin pool cleaner parts, or check your model's steps in the Dolphin cleaner manuals.

Frequently Asked Questions

Why is my Dolphin pool cleaner not climbing the walls?The most common cause is a full or dirty filter reducing suction, followed by tangled or worn brushes. Trapped air, a blocked impeller, worn tracks, algae-covered slippery walls, or a floor-only cleaning mode can also stop it climbing. Work through these in order and most cases resolve quickly.
How do I fix weak suction on my Dolphin cleaner?Clean the filter basket or cartridges thoroughly, then check the impeller for trapped hair or debris. A clogged filter and a blocked impeller are the two main causes of weak suction, which in turn stops the cleaner climbing walls.
Should I clean my pool walls before running the cleaner?If the walls have an algae film, yes. A slippery, algae-coated surface prevents the cleaner from gripping. Brushing the walls and balancing your water chemistry restores traction.
Why does my Dolphin float instead of sinking and climbing?Trapped air makes the unit buoyant. Lower it into the water at an angle before each cycle and let the air bubbles escape so it fully submerges and settles on the pool floor.
Do worn brushes stop a Dolphin from climbing?Yes. Brushes worn smooth or clogged with hair lose the grip needed to climb walls. Cleaning or replacing the brushes usually restores climbing performance.
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