Robot Pool Cleaner Moving in Circles or One Direction? Fixes

What is going wrong

• 1Stored twistTwist held in the cord biases the machine the same way every cycle and unwinds itself onto the drive.
• 2Unequal driveOne track slowed by debris or wear is a permanent steering input, and a permanent steering input is a circle.

Why this happens

Most robotic cleaners steer by driving two tracks or wheel sets and turning by running them at different speeds. When one side slows or stops, the unit pivots toward the stalled side and circles. A stone or wad of debris lodged in a tread, a worn or slipped track that no longer grips, or a drive motor weak on one side all produce that imbalance. A cable that is twisted or too short also pulls the unit around, which can look like a drive fault when the real cause is drag from above.

Fix it in order

Work through these from the top. Unplug the unit before you reach near the tracks.

1. 1

   Tracks checked

   Clear both tracks.

   Turn the unit over and pick out stones, leaves, and hair wound around the axles and tread. A single jammed side is the most common reason it circles.

2. 2

   Cable relaxed

   Untwist the cable.

   Lay the full cable out straight and let it relax. A coiled or knotted cable tugs the unit and steers it in an arc. Many cables take a set and benefit from being stretched out in the sun.

3. 3

   Tracks checked

   Check that both sides spin freely.

   With power off, turn each track by hand. One side that resists or will not turn points at a jam, a seized bearing, or a drive fault on that side.

4. 4

   Tracks checked

   Inspect the tracks for wear.

   Look for a track that is stretched, cracked, or has slipped off its drive gear. A slipped or bald track spins without gripping and the good side pushes the unit in a circle.

5. 5

   Cable relaxed

   Confirm the cable length.

   A cable too short for the pool goes taut and drags the unit back along one path. Give it enough slack to reach the far end without pulling.

6. 6

   Flow restored

   Test on a clean, flat section.

   Run it on open floor away from walls and steps. If it tracks straight there, the earlier circling was debris or an obstacle, not the drive.

If it still veers

• It always turns the same way. A consistent direction points at one specific side, so focus on that track, axle, and motor.
• One track runs slower than the other. Watch both sides in the water. A visibly slower side with clean tracks suggests a weakening drive motor on that side.
• It only circles near the cable. If the arc follows the cable, the drag is from above and the tracks are fine.
• A track keeps coming loose. A track that slips off repeatedly is stretched or the gear is worn, and it is a routine replacement part.