What Does This Error Mean?

Error Code 3 on a Dolphin pool cleaner (3 flashing LED lights on the power supply) indicates a motor fault — most commonly the impeller motor. Check for debris blocking the impeller basket or brush assembly first. If the impeller spins freely by hand and the error persists, the motor or drive board needs replacement.

Affected Models

Dolphin Nautilus CC
Dolphin Nautilus CC Plus
Dolphin Sigma
Dolphin Premier
Dolphin E10
Dolphin S300i

Common Causes

Debris jammed in the impeller motor blocking rotation
Motor brushes worn after extended use causing overcurrent
Impeller motor overheated — insufficient cooling flow
Water ingress into the motor housing causing internal short
Blocked suction port reducing flow through the drive motor

How to Fix It

Remove and inspect the impeller/filter basket.

Remove the top lid and lift out the filter basket. Check the impeller area beneath the basket for large debris — leaves, twigs, or small stones can jam the motor. Remove all debris, then replace the basket.
Spin the impeller by hand.

With the cleaner out of water and unplugged, reach into the impeller housing and try to spin the impeller blade by hand. It should rotate with slight resistance but not feel seized. A seized impeller confirms a motor jam or bearing failure.
Power cycle and retry.

Unplug the power supply for 60 seconds to clear the fault state. Plug back in and place the cleaner in the pool. If the error code reappears within the first few minutes, the motor fault is confirmed.
Check the brush roll for tangles.

Hair and fibres wrapped tightly around the brush axle can load the drive motor enough to trigger Error Code 3. Remove the brush and cut away any wrapped material. Some Dolphin models have a tool-free brush removal clip.
Contact Maytronics support.

Dolphin cleaners are manufactured by Maytronics. If the cleaner is under warranty (typically 2 years), contact Maytronics or your authorised dealer. Error Code 3 on a relatively new cleaner often qualifies for warranty motor replacement.

When to Call a Professional

If no debris is found, the impeller spins freely, and Error Code 3 still appears after a reset, the motor windings or drive board are likely damaged and need professional service or replacement.