Weak suction almost always traces to a clogged filter or a blocked impeller restricting water flow. Clean the filter, clear the impeller, purge trapped air, and inspect the seals — if suction still fades, upgrade to high-capacity NanoFilters so the robot doesn’t choke as it fills.
Free the water flow
Robots clean by pulling water (and debris) through the filter and out the top. Anything that restricts that flow shows up as lost suction. Start by rinsing the filter, then clear the impeller of hair and leaf stems, and release any trapped air that can break the seal against the floor.
Check the seals and cartridge fit
A filter that isn’t fully seated, a warped lid, or a cracked seal lets water bypass the filter and kills pickup. Make sure every panel clicks in and the cartridges aren’t deformed or cracked. Look for a hairline split in the impeller housing too.
Stop the mid-cycle fade
If suction is strong at the start but fades fast, your filter is filling too quickly for its capacity. NanoFilters™ and MaxBin™ robots hold far more debris before flow is restricted, so you get consistent suction for the whole cycle — a big upgrade during pollen season or after a storm.
When it’s the motor
If the filter and impeller are clear and suction is still weak, the pump motor may be worn — common on older units near end of life. Our experts can help you decide between service and replacement; browse current models on our robotic pool cleaners page or contact us.
