Dear Peter,
It probably reads AL5 and means that water is not getting into your machine. Probably a faulty solenoid valve -- mine has given up the ghost twice and they are quite cheap (£25-30) and easy (couple of screws off the back) to repair.
It also could be a twisted inlet hose though -- so just check all your hoses before you part with your cash...
Paul Hazell (Wantage UK), January 2007
