I use the grey water for gardening so the pipe is clear.Check your outflow/drain hose. If it fits too tight in the drain pipe some times a siphon will be set up. When you are trying to fill it the siphon action keep draining it preventing it from getting full enough to start the cycle.
The water is going out as fast as the water comeing in. The washer dosen't fill at all.How fast does it drain? Is the washer running while it drains? Is the pump running?