Maytronics Dolphin Rapid Drain Flap

The Maytronics 9983102 is the genuine rapid drain flap for the Dolphin S200, S300, S300i, Active 20, Active 30, Active 30i, Triton PS and Triton PS Plus robotic cleaners. It is a small part with two jobs, and the robot misbehaves in a recognizable way when it stops doing either of them.

What it does

The flap sits at the rear bottom of the cleaner over the drain port. When you lift the robot out of the pool it swings open and the water inside runs out, which is why a Dolphin is light by the time it reaches the deck. While the cleaner is running, the flap stays closed so the pump pulls water and debris through the filter rather than the drain.

When it fails

A flap that no longer seals lets the cleaner vacuum debris in through the drain port during the run. That debris tends to collect in the top exhaust port, so a robot that keeps packing leaves into its exhaust is usually asking for a new flap. Maytronics lists it as a wear item, so it is a normal replacement over the life of the machine.