You may have a Navigator with the 4 feet and wings, people call them R2D2’s. While the pump is running carefully put your index finger, the long one, in the hole on the bottom of the cleaner try to feel the water wheel paddles moving, if not then try to move the wheel with your finger.

If it starts moving then all is well. Sometimes grit or glass gets inside and stops them from moving. Rodents work well too. Turn it over holding under water to see if you see a tail!
If the wheel is clear, check your filter it likely needs cleaning since these cleaners are suction side and affected by dirty filters.

Pro Hayward – from ScubaBob:

The Hayward Navigator is a good one. They swallow just about anything in their way but they do have an issue regarding the mesh on the turbine intake on the back of the unit. You need to watch to see that it doesn’t get clogged with debris. That inlet provides one of the turbines water, that in turn powers the turning gears that stop the cleaner from getting hung up in a corner or against a wall. Easy to fix, but annoying if you get fine debris clogging it all the time.
The other good one, that’s virtually bomb proof but can be a picky eater ( hates twigs) is the Kreepy Krauly. They are so simple in design that there’s virtually nothing that can go wrong with them and they work pretty well.

From Stateof:

I’ve used the Dolphin Pool Cleaner and it works very well. Good for sand, and small stuff, not so much big leaves and what not, but thats what a skimmer net is for.