My Hoover HND 325 Stuck on rinse cycle?

My Hoover HND 325 is stuck on cold rinse cycle. To switch on the cold rinse I pressed the rapid and half load buttons simultaneously. It seems to be sucking water in for a second or two, flashes both lights and stops. Then it happens again and again with a few seconds in between. Occasionally, it empties a small amount of water.
I have tried to press the main wash button for over 5 seconds but this does not do anything. It carries on attempting to cold rinse. Is there a way I can reset the machine?