How pool robot fault lights work

The lights on a pool robot are the robot's way of telling you what it just noticed. A control chip watches the motors and sensors. When a reading looks wrong, it flips a light, a beep, or both.

That's all a "fault light" is. It isn't a diagnosis. It's a hint pointing at one area: power, motor, filter, or something that stopped the cycle.

What's inside that can trigger a light

An electric robot is a self-contained machine with its own pump and its own filter. One source describes it as independent of the pool's main filter and pump system¹.

Inside there are two motors. One pulls water through the filter. The other drives the tracks. A small chip runs the drive motors¹.

So when a light shows, the chip has usually noticed one of these:

• The pump motor is working too hard or not at all.
• A track or wheel isn't turning.
• The filter is so full that water barely flows.
• Power from the supply or battery is missing or dropping.
• The robot lost contact with the water, or got stuck.

Why one maker's pattern isn't another's

There's no shared standard. Each maker picks its own colors, blink speeds and beeps. The same color can mean opposite things.

Look at one maker's own support page for a cordless robot. Red is listed as "Red – Low Battery (2024) / Device Malfunction (2025)"². The red entry carries two labels, "Low Battery (2024)" and "Device Malfunction (2025)", so check your own manual for which applies.

That page also lists purple as "Solid Purple – Device is stuck" and the slow blue blink as "Flashing Blue Every 3 Sec: Device is idle"².

Another maker's page says a robot's light can blink "in intervals or 1 second" when the battery is running out³. A blink there is a battery message, not a motor message.

Solid, flashing, or beeping

Roughly, and only roughly:

• Solid lights on that cordless robot show states like working, fully charged, or a malfunction².
• Flashing lights on the same robot show things like starting, charging, idle, or low battery².

Treat that as one example, not a rule for every robot. Your manual's table wins every time.

What to do the moment a light shows

Don't reset first. A maker-neutral repair guide makes the point well: write down the exact light and beep pattern first, because that is what tells you and support which fault it is⁴.

So write down:

• The color of the light.
• Whether it's solid or blinking, and how fast.
• Whether there were beeps.
• What the robot was doing when it happened.

Then switch the robot off before you touch it. Safe checks before you touch a faulty pool robot walks through that order.

Next, find the table for your exact robot. How to find your fault code in the maker's manual covers where it lives.

One maker's support page says each robot's cleaning path setup is different, and tells you to check the user manual for your model³.