Louise,
At the back is a solenoid valve which controls the input of the water, when you turn the machine on do you hear a click from where the hose goes into the machine? if not the valve is possibly faulty, if so its an easy job to get one and replace. If you hear a click and it still doesn't work then the filter sieve at the valve might be blocked with grit out of the water. Turn off the valve to the hose. disconnect the hose from the machine and pull out the little plastic sieve and clean. If these are not the problem it's probably something more than you can deal with so call a man but guard your purse, pounds have a habit of escaping!
IanT, May 2006