We have a Polaris 280 pool robot which I must say is a wonderful tool and quite fascinating to watch.
We have had it about 10 months and up until last week it has performed as it should - although the blighter wont climb the steps which is irritating because I have to brush them off manually - but last week we noticed that a lot of wind blown soil debris had accumilated in the corners and on the floor which the normal filter cannot deal with.
The tail which blows out a jet of water was 'limp' and not doing as it should. On inspection of the Polaris there a appeared to be a distinct lack of pressure but we noticed it also rose and dropped without a real pattern.
I carried out all of the troubleshooting procedures the manual had suggested which included cleaning the in line filter, washing out the bag and re-setting the head float. Inspection of the hoses revealed no holes or leaks and the booster pump seemed to be operating normally.
I took out the Universal Wall Fitting which connects the hose to the pool wall and back to the pump and looked at the pressure restrictor disk but there was no blockage.
A lot of humming and haghing went on and we repeated the procedures a few times but nothing!
We put it all back together again only to find that the pressure was almost non existent. Again we checked everything and then....................a brainwave!
I felt sure something was restricting the pressure but nothing was revealed on inspection but what we did not do when the UWF was out was to run the pump to flush anything out. We unscrewed the collar that holds it in and switched on the pump. Out rolled a round solid ball of muck the size of a marble.
We didn't like to count chickens but when we put it all together again and turned it on the Polaris did somersaults around the pool and the tail could not stop wagging.
So, if you have a simmilar device and the pressure seems poor, don't rush off for a new pump, try what we did (which is not suggested in the manual).