Restoring the drier function.
Using a carefully made peice of bent wire it is possible to remove the fluff on the fan baldes. It needs to be about 12 inches long with a 1/4 inch 90 degree hook on the end.
Undo the clips retaining the upper hose that runs down to the condenser unit (back right).
With a bright light look down into the unit and you will see the edges of the fan all clogged up with fluff.
Assuming you have turned to main power off, gently pick off the fluff with the wire hook. Rotate the fan, one blade at a time (rotate the fan motor) until you have picked it off all the blades. There are about 30 blade sin all. The use a vacuum cleaner to pull all the residual bits off as you slowly rotate the fan.
Put the hose back on (that nasty spring hose clip will fight you all the way). Hit the heater reset button (middle right side of the heater block).
Job done.
After about 12 years the condenser unit as a whole needs to be refurbished (a big job but well within DIY territory) as there will be considerable corrosion at the inlet. Or you can replace it at a cost of about £350, but you would be mad to do so as a new Hotpoint washer-drier is cheaper and once your machine is at this stage in its life the main drum bearing is about to fail anyway.
Barney46
August 2014