Most robots that get replaced were not broken in any expensive way. They had a worn wear part, a clogged filter, or a failed transformer that costs a fraction of the machine.
Start from the symptom and work down. The order below is roughly the order of how often each cause turns out to be the answer.
If yours has no power supply and runs on water from the pool's own pumps, it's a suction or pressure-side cleaner, and the guide to a pool cleaner that won't move is the one you want.
Key takeaways
- Most dead robots are a failed power supply, which is the cheapest part in the system.
- Stopped climbing walls means brushes or a full basket long before it means a motor.
- Run the robot with the pump off. Return current pushes it off its pattern.
- A robot that floats has air trapped in the housing — put it in at an angle.
- Cable tangle is a symptom of storage, not of the robot.
It won't power on
Check the GFCI first. Pool circuits trip, and a tripped outlet looks identical to a dead robot. Reset it and try again.
Then suspect the power supply. The transformer box is the single most common failure in a robotic cleaner system, and it is not part of the robot. If you can borrow another unit's supply, or get yours tested, do that before you conclude anything about the machine.
Then the cable. Look for a cut, a crush point where a deck chair has sat on it, or a section that has been twisted in the same direction for years. Internal conductor breaks are invisible from outside and usually show up as intermittent operation before total failure.
The motor is last. In practice most "dead" robots are one of the three above.
Robotic pool cleaner won't climb walls
This is the most misdiagnosed symptom in pool equipment, and it is almost never the motor.
Worn brushes. Brushes lose grip gradually, so the robot climbs a bit less each month until one day it stops. If the rubber is smooth where it used to have texture, that is your answer. $30 to $60, ten minutes.
A full filter basket. A loaded basket makes the motor work harder and changes how the water moves through the machine, and climbing is the first thing to go. Empty it after every cycle rather than when it looks full.
A slick waterline. Biofilm on the tile is genuinely slippery. If the scum line has been left, the robot may be doing everything right and simply sliding.
Water level too low. If the surface sits well below the tile, there is nothing above the waterline for the robot to reach and it will look like a climbing failure.
It stops part way through a cycle
Overheating power supply. Sitting in full sun, transformers thermally cut out and restart. Shade it and see if the behavior changes.
A jam in the drive train. A hair tie, a leaf stem, a piece of plastic wrapped around a drive shaft. Open the housing if the design allows it and clear it — this is a cheap fix that ends a lot of machines because nobody looks.
Cable tangle. The robot has not stopped, it has run out of cable and is tethered. See below.
It finished. Worth ruling out. Cycle lengths vary by mode, and a short mode on a large pool ends before the pool is covered.
It only cleans part of the pool
- 1
Turn the pump off and re-run it
One cycleThis is the fix more often than anything else. Return jets push a surprising amount of water across a pool, and a robot working against that current gets held in one zone and never crosses.
Robots are designed to run on their own. Filtration during a cycle is working against you.
- 2
Check the cable reaches
5 minutesMeasure the pool diagonal, add the depth, add a few feet to the power supply. A cable that is a few feet short cannot reach the far end and nothing else will fix that.
- 3
Untangle and relax the cable
1 hourA tangled cable tethers the robot short, and it looks exactly like poor coverage. Lay it out straight in the sun for at least a day, the time Hayward's and Maytronics' manuals give, and let the memory come out of it.
- 4
Look at what it's avoiding
One cycleWatch a cycle. Ladders, steps, main drain covers and sharp corners all deflect a robot, and some navigation systems handle them much better than others. A machine that consistently abandons the deep end has a pattern problem rather than a fault.
Some stops are part of the program, too. Hayward's manual for the SharkVac says it may stop in the middle of the pool and reverse, and that it can sit on a raised main drain for a while before its program frees it.
It leaves fine debris behind
The filter media is the first thing to check, and not just whether the basket is full.
Filter panels clog progressively at a level you cannot see — the basket looks empty while the media is blinded with fine silt and pollen. Rinse the panels themselves under a hose, from the clean side outward, rather than just tipping the basket.
If your model takes different media grades, fine cartridges catch pollen and silt that the standard ones pass straight through. That is often the whole difference on a pool under trees in spring.
Worn brushes show up here too. A robot that is not agitating the surface is only picking up what has already settled loose.
It floats
Air trapped inside the housing.
Lower it into the water at an angle rather than dropping it in flat, and give it a moment to purge before starting the cycle. Most robots need this every time and the manuals rarely make it clear.
If it still floats after purging, either the filter panels are clogged solid enough to hold air, or a seal has gone and the housing is holding water it cannot drain — which is a repair rather than a technique problem.
When it isn't worth fixing
The honest line is parts availability, not age.
A machine whose manufacturer sells brushes, tracks, a power supply and a drive motor is worth repairing almost indefinitely. A machine whose manufacturer sells nothing was a consumable from the day you bought it, whatever it cost — and that is worth knowing before the next one rather than after.
That single question is why the robotic cleaner picks weight repairability the way they do.
Go deeperStop it happening againThe fifteen minutes a month that takes a robot from five years to ten.Frequently asked questions
Why won't my robotic pool cleaner turn on?
Check the GFCI outlet first, then the power supply. The transformer box is the most common failure in the whole system and often the cheapest part to replace, which is why so many working robots get thrown away. Before you condemn the machine, try the power supply on another unit or have it tested — a robot that is genuinely dead is unusual.
Why has my robot stopped climbing the walls?
Worn brushes, nine times out of ten, and a full filter basket the rest of the time. Brushes are a wear part that lose grip gradually, so the robot climbs a little less each month until one day it does not. They cost $30 to $60 and take about ten minutes. People replace whole machines over this.
Why does my robot only clean part of the pool?
Usually the pump. Running filtration during a cleaning cycle puts current across the pool that pushes the robot off its pattern and holds it in one area. Turn the pump off and run the robot on its own. After that, check the cable is long enough for the pool diagonal and is not tangling and tethering the machine short.
Why does my robotic cleaner float instead of sinking?
Air trapped inside the housing. Lower it into the water at an angle rather than dropping it in flat, and let the air escape before you start the cycle. If it keeps floating after that, the filter panels may be clogged solid enough to hold air, or a seal has failed and the housing is taking on water it cannot drain.
Is it worth repairing a robotic pool cleaner?
Usually, if the brand sells parts. Brushes, tracks, a power supply and even a drive motor are all reasonable repairs on a machine designed to be opened. It stops being worth it when the manufacturer sells nothing — at that point the machine was a consumable regardless of what it cost, which is why parts availability matters more than suction claims when you buy.
