By Shaz · Updated September 2026
Dolphin Pool Cleaner Starts Then Stops? Causes & Fixes
A Dolphin that powers up, runs briefly and then stops is the most-reported Dolphin fault — and in most cases you can fix it yourself in ten minutes. The robot's electronics deliberately shut the motors down when something restricts them, so your job is to find the restriction. Work through these causes in order.
1. Clogged or full filter (the cause in most cases)
A packed filter starves the pump motor, the motor draws too much current, and the protection circuit stops the robot. Open the filter compartment, empty it and rinse the panels under a tap until water runs through freely. Ultra-fine panels blind quickly during algae season — rinse after every cycle.
2. Jammed impeller
Hair, string, leaves or a pebble wrapped around the impeller has the same effect as a full filter. Disconnect power, remove the impeller cover (usually a few screws on the top of the robot) and clear everything from the blades. Spin it by hand — it should turn freely with a light click.
3. Overheating power supply
A power supply baking in direct sun shuts down to protect itself, taking the robot with it. Move it to shade, off hot stone, with airflow around it — and never cover it while running. If it cuts out on hot afternoons but works fine in the morning, this is your cause.
4. Damaged floating cable
Inspect the full cable length for cuts, kinks or a crushed section (deck furniture is the usual culprit). A damaged conductor makes intermittent contact — the robot stops each time the break opens. A damaged cable needs replacement by a service centre; don't tape and continue, since it carries the robot's power.
5. Drive problem disguised as a stop
If the pump keeps running but movement stops, that's a different fault — see Dolphin turns on but won't move.
Reset and retest
After each fix, do a proper reset — power off, 30 seconds unplugged, restart (full reset steps here) — and run a cycle with the pool pump off. If the robot still stops after all five checks, the fault is internal (motor unit or control board) and should go to an authorised service centre under warranty. To stop this happening again, the filter-rinse and monthly checks in our maintenance guide prevent nearly every cause above.
Models in this guide:Browse all Dolphin models or see every comparison.