By Shaz · Updated September 2026

Dolphin Pool Cleaner Troubleshooting: 12 Common Problems & Fixes

Dolphin robotic pool cleaners are famously reliable, but every robot eventually has an off day. The good news: most Dolphin problems have simple causes — a clogged filter, a worn brush, a tangled cable — that you can fix yourself in minutes without a service visit. This guide covers the twelve problems owners report most, with the fix for each. It applies to every Maytronics Dolphin model, from the Nautilus CC Plus to the M700.

1. Dolphin won't turn on at all

Check the obvious first: is the power supply plugged into a working GFCI outlet, and is the cable firmly clicked into the power supply socket? Try another outlet. If the power supply shows no light at all, it may have failed — power supplies are sold separately and are the most commonly replaced electrical part.

2. Dolphin starts then stops after a few seconds or minutes

This is almost always one of three things: a full or clogged filter (empty and rinse it), debris jammed in the impeller (unscrew the impeller cover and remove hair, leaves or pebbles), or an overheating power supply sitting in direct sun. We cover this in detail in Dolphin starts then stops: causes and fixes.

3. Dolphin turns on but won't move

If the pump motor hums but the robot sits still, the drive system is the suspect: check for a stretched or derailed track, debris wedged between the track and the body, or a worn drive belt. Full walkthrough: Dolphin not moving: 6 fixes.

4. Not climbing walls

Wall climbing depends on suction and grip together — worn brushes, a full filter or algae-slick walls all stop the climb. See our dedicated guide: Dolphin not climbing walls.

5. Not picking up dirt

Usually a filter issue: the filter is full, the wrong filter grade is fitted (rough-debris panels let fine dust straight through), or the filter door isn't latched so debris washes back out. Details: Dolphin not picking up dirt.

6. Robot floats and won't sink

A brand-new Dolphin (or one that's been stored dry) traps air in the body and floats. Hold it underwater and rotate it until the bubbles stop before releasing it. If a robot that used to sink now floats, check for a cracked body panel trapping air, and make sure the filter compartment is fully closed.

7. Tangled floating cable

A twisted cable shortens the robot's reach and leaves parts of the pool dirty. Spread the full cable loosely on the deck before each run, and after each cycle let it hang straight to untwist. Models with a swivel cable resist tangling; if the swivel has seized, it can be replaced. More in fixing a tangled Dolphin cord.

8. Gets stuck on the main drain or a fitting

Strong main-drain suction can pin a robot in place. Run the Dolphin with the pool pump off (it doesn't need the pump anyway), and it will pass over the drain freely. Robots can also snag on raised fittings, ladders and steep cove angles — repositioning the ladder or running a shorter cycle usually avoids the spot.

9. Needs a reset

Dolphins don't have a visible reset button — the reset is a power-cycle sequence on the power supply. The exact steps are in where is the reset button on a Dolphin pool cleaner.

10. Cleaning cycle too short or robot misses areas

Untangle the cable (problem 7), clean the filter, and make sure you selected the full cycle rather than a quick mode. On app-connected models, check MyDolphin™ Plus for the active cleaning mode.

11. Error light on the power supply

A blinking indicator usually signals an impeller jam or motor overload. Disconnect power, clear the impeller and brushes, and restart. If the light returns immediately with a clean robot, contact your dealer — it may be a motor or cable fault covered by the warranty.

12. Robot works but smells or the pool stays cloudy

Cloudy water isn't the robot's job alone — check your pool chemistry and circulation. A musty smell means the robot was stored wet: rinse it with fresh water after every use and store it dry on its caddy, out of the sun.

When to stop DIY and use the warranty

Anything involving the motor unit, internal electronics or a damaged cable jacket is a job for an authorised Maytronics service centre — opening the sealed motor unit yourself voids the warranty. For routine care that prevents most of the problems above, follow our Dolphin maintenance guide.

Models in this guide:

• Dolphin Nautilus CC Plus Wi-Fi — full review & specs
• Dolphin M700 — full review & specs
• Dolphin Premier — full review & specs

Browse all Dolphin models or see every comparison.