When the Smartpool NC22 Robotic Pool Cleaner is ruining, it sucks water into the Filter Bag through two intakes in the front of the Cleaner and two in the back. When the Cleaner shuts off, a spring loaded flap closes off each of these intakes to prevent debris in the bag from escaping back into the pool. If these flaps are damaged or fail to close, they should be replaced. This guide shows you how to replace the Front Intake Flap(s) on a Smartpool NC22 Robotic Pool Cleaner. Note: Although this guide features the NC22 model cleaner, these instructions can be used for replacing the Front Intake Flaps on other models of Smartpool Robotic Pool Cleaners that use these Front Intakes.