# Dolphin pool robot not picking up debris: causes and fixes

A Dolphin that moves but doesn't pick up debris almost always has a clogged filter or debris in the impeller housing. Maytronics' fix is to clean the filter after every cycle, clear the impeller and use the right filter for the dirt in your pool.

Updated Oct 27, 2026. HTML version: https://robotsforthat.com/guides/dolphin-pool-robot-not-picking-up-debris/

## Short answer

Maytronics' troubleshooting table gives two causes for a Dolphin that moves but does not clean: a clogged filter and debris in the impeller housing or cover. Rinse the filter basket after every cycle and the ultra fine panels at least monthly, then unplug and clear the impeller. If it leaves whole areas dirty, move the power supply and release more cable. Use the coarse net filter for leaves and the ultra fine panels for fine dirt.

| What you see | Likely cause | Fix |
|---|---|---|
| Moves around but leaves dirt behind | Clogged filter | Unplug, open the filter cover and rinse the basket with a hose after every cycle. |
| Moves but does not clean, and turns one way only | Debris in the impeller housing or cover | Unplug, remove the impeller cover, clear the debris and refit it with a hand Phillips screwdriver. |
| Steady orange On/Off LED | Filter clogged (selected models) | Clean the filter. |
| Fine dust and silt pass straight through | Coarse net filter in use for everyday dirt | Use the ultra fine panels for daily cleaning. They are the factory default. |
| Leaves pack the filter within minutes | Fine filter in a very dirty pool | Use the net or spring filter at the start of the season. Inyo Pools suggests cleaning the filter about every 30 minutes in a very dirty pool. |
| Filter dried out with dirt in it | Panels left to dry before cleaning | Rinse the panels while they are wet. Maytronics says not to let them dry before cleaning. |
| Same areas stay dirty every run | Power supply badly placed or too little cable released | Place the supply mid way along the long side, about 3.5 m (12 ft) from the edge and 11 cm (4 in) up, and release enough cable for the far corner. |
| Robot drives in circles | Clogged filter, impeller debris, supply position, or algae and water out of range | Clean the filter and impeller, reposition the supply and correct the water. |
| Filters clog with a sticky film | Liquid flocculant or clarifier in the water | Maytronics says not to run the robot after adding these, since they clog and damage filters. |
| Debris left on walls and steps | Algae, or the robot is not climbing | Brush algae off before the first run of the season. See our Dolphin not climbing walls guide. |

## Step by step checks, in order

A Dolphin picks up dirt by pulling water through its filter with the impeller. If either is blocked, the robot still drives but stops collecting. Do these checks in order.

- Turn off and unplug the power supply.

- Open the filter cover, lift out the basket, open the latch on the bottom lid and rinse out the debris with a hose.

- Once a month at least, remove the inner net basket, take out the four ultra fine panels one by one, rinse them and reassemble them in reverse order.

- Remove the impeller cover, clean around the impeller and refit it with a hand Phillips screwdriver. Maytronics says not to use an electric screwdriver.

- Check the On/Off LED. Steady orange on models that have it means the filter is still clogged.

- Run a cycle and check the basket afterwards. Debris in the basket means pickup is working.

## Use the right filter for your dirt

Recent Dolphins ship with a coarse net filter and ultra fine panels. Maytronics says the net filters are for large debris and the start of the season, and the ultra fine panels are for daily use. The older Supreme manual describes the same split: a spring filter for dirty pools and season start, and an ultra fine cartridge for everyday use.

If leaves and twigs fill the fine panels in minutes, swap to the coarse filter until the pool is clear. If fine silt is passing through, go back to the ultra fine panels. Make sure the filter elements are seated with their tabs in the base frame grooves and the clips closed; the older manual lists open filter doors and a badly mounted cartridge as causes of poor coverage.

## When it cleans only part of the pool

A robot that skips whole areas is usually limited by its cable, not its suction. Maytronics says to place the power supply near the middle of the long side of the pool, at least 3.5 m (12 ft) from the edge and at least 11 cm (4 in) off the ground, plugged into a GFCI protected outlet without an extension cord. Release enough floating cable to reach the farthest corner without kinks.

If the cable is kinked, Maytronics says to stretch it out fully and leave it in the sun for at least a day. Algae and water chemistry out of range also cause circling, so keep pH at 7.0 to 7.8.

## When to replace a part, contact support or replace the robot

Filter panels and baskets are wear parts. If the mesh is torn or the panels no longer seat, replace them with Maytronics parts from your dealer. If the impeller is clear and the filter is clean but suction stays weak, the motor unit may be failing, which is a dealer or warranty repair.

Maytronics lists North America customer support at 1 888 365 7446 ext. 1002 and customersupport@maytronicsus.com. Have the model and serial number ready. If an out of warranty robot needs a new motor unit, compare that quote with a new robot before you buy the part.

## Questions people ask

### Why is my Dolphin running but not picking anything up?

Maytronics lists a clogged filter and debris in the impeller housing or cover. Clean the filter, then unplug and clear the impeller.

### How often should I clean the Dolphin filter?

Maytronics says to rinse the basket after each cycle and the ultra fine panels at least monthly. In a very dirty pool, Inyo Pools suggests about every 30 minutes.

### Which Dolphin filter should I use for leaves?

The coarse net or spring filter, which Maytronics recommends for large debris and the start of the season. Use the ultra fine panels for everyday fine dirt.

### Why does my Dolphin miss the same spots?

Usually the power supply is badly placed or too little cable is released. Move the supply to the middle of the long side, about 12 ft from the edge, and release more cable.

## Sources

1. [Maytronics: Dolphin M700 / TOP 15+ user instructions](https://manuals.maytronics.com/images/pdfs/8181000-EN.pdf)
2. [Maytronics: Dolphin CLASSIC 10 / 10+ user instructions](https://brand.maytronics.com/m/649fdcb0372574c3/original/User-manual-8180033-EN.pdf)
3. [Maytronics: Dolphin CLASSIC 8+ / TOP 8 user instructions (hosted by Poolbots)](https://www.poolbots.com/assets/manuals/sigma-manual.pdf)
4. [Maytronics: Dolphin Supreme M4 user instructions (hosted by Esta Poolshop)](https://www.esta-poolshop.de/tpl/download/M4.pdf)
5. [Inyo Pools: How to maintain a Maytronics Dolphin Nautilus](https://support.inyopools.com/hc/en-us/articles/47441887312283-How-To-Maintain-a-Maytronics-Dolphin-Nautilus-Robotic-Cleaner)