Pool Robot Guides & Troubleshooting

There is a correct order to diagnose a pool robot, and it is not the order most people use. Most people start by suspecting the expensive component. The right order starts with the free checks, because the free checks are also the most likely causes.

The free five, in order

1. Empty and rinse the filter. A blinded filter causes low pickup, failed wall climbing, short effective cycles and motor-overload errors — four different-looking symptoms with one cause.
2. Clear the intake and impeller housing. A leaf plug in the throat is invisible from outside and stops the machine collecting anything.
3. Check every rotating shaft for a debris wrap. Pine needles, hair and grass wrap brush and wheel axles and load the drive motor continuously.
4. Look at the brushes. Flat equals no grip. That is the wall-climbing answer, and it is visible in thirty seconds.
5. Check the water level. Low level breaks surface skimming, puts a waterline pass above the actual ring, and on some machines triggers a fault.

Only after those five does it make sense to buy anything. The full troubleshooting index maps every symptom to its usual cause.

The parts that fix the rest, with real prices

• Failed wall climbing → brushes ($23-30) then tracks ($35) — the brush page has the part numbers.
• Will not charge → charger ($10-17) first, then battery ($69-80 where available) — what exists, by model.
• Suction gone with a clean filter → pump motor and impeller assembly (about $110 on a Dolphin). A real teardown, and a repair rather than a replacement.
• Pushes sand around instead of collecting it → a finer filter ($19-33). This is a filtration problem, not a suction one — the micron explainer covers why.

Three faults that mean stop

Water inside the housing, any burning smell, a swollen battery pack, or a damaged cable on a corded machine. None of those is a home repair. Water ingress in particular will destroy the motor and electronics if you keep running it, and a damaged low-voltage cable in a pool is a safety matter rather than an inconvenience.

The ownership questions worth answering before you buy

Four of the guides above will save you money whether or not you own a robot yet. Whether one is worth it at all turns on pool size and how often you swim, not on cleaning quality. What one actually costs to run is mostly about pump time rather than the robot’s own draw. How long one lasts depends almost entirely on whether a replacement battery is sold for that model. And how often to run it has a counterintuitive answer: more often, for shorter periods, because once the basket is full the rest of the cycle collects nothing.

The problem guides, and what they will not promise

Seven of the guides above are problem-first: leaves, algae, sand, the waterline, and three for when you are missing equipment. Two honest notes about them.

First, a robot does not kill algae. Algae is a living biofilm anchored to your plaster or liner and it is killed by chemistry. What a robot does is break the film open so the sanitizer can reach it, then filter out the dead cells. The wall-algae guide sets out the correct order, and it starts with a test kit.

Second, several of these guides will talk you out of a purchase. The no-vacuum guide shows how far you can get with a flat leaf rake, a brush and your existing filtration, and where that genuinely stops working. We would rather you bought the right thing, or nothing, than the expensive thing.

What we do not do on these pages

We do not publish manufacturer error-code tables, because they are model-specific, change between hardware revisions, and the versions circulating online are frequently copied from the wrong model. A table we cannot source would look more useful and be less useful — so that page teaches you to read the four fault categories instead and links each manufacturer’s own support entry point.

And we do not physically test pool cleaners. Every figure on this site is attributed to a manufacturer specification, a retailer listing, or marked as not published — the methodology page sets out exactly how we work.