Hi. I have a back pressure problem. I recently sealed the connections just before the pump, and the cleaner went working normally. But I have back pressure when the pump is switched off. Pool service nearby advised it could be my filter sand. But I replaced the sand 2 months ago. Is there advice you can offer on the breather pipe in the filter? The cleaner is no longer working as it should. The diagnosis from the pool service centre is that the breather pipe was not placed back properly and therefore causing back pressure and finally causing the cleaner to default. Please help. Thanks.