Darren,
This fault is common and usually due to the 'one shot' stat gone.  They come as a kit and are located just above the heater element behind the rear cover.  Just a matter of removing about a dozen screws.  Remember to power off before replacement.  We can supply the thermostat kit from here:
http://www.ukapplianceparts.com/laundry.asp?search_fd3=Thermostat%20Kits&search_fd4=hotpoint&multisearch_fd4=5
You need part number 1701583 - the first on the list.
                
 Lee
                
 November 2006