Cold water not filling Fisher Paykel ecosmart GWL11 washer?

When I turn on my Fisher Paykel ecosmart GWL11 washing machine selecting cold water I only get a tiny burst of water followed by a dribble. After 4 minutes the machine does its musical beeping and the hot and cold lights flash red simultaneously. The hot water is working perfectly. I have disconnected the hose at both ends and nothing is clogged. With the cold hose attached to the wall and disconnected from the machine I have tested it and plenty of water comes through the hose. The small white plastic filter inside the washer connection is also clean. Is there anything else I can check or is it time to call a repairman?