I finally got mine fixed by persaverance and trial and error.
Now if i can do it anyone can - I'm no engineer and can just about wire a plug :-)
1) Unplug!!
2) Unscrew 2 Screws on the back at the top. Then take the top off - it needs a bit of force not too much though. I found lfting the back end and firmly tapping the front with the heel of my hand worked and didn't break anything.
3) On the right hand side is a large metal snail sort of shape metal thing with wires on. Make a note of which wires go where and unplug them all. (One of these although I didn't need to buy and replace this http://shop.ukwhitegoods.co.uk/Washing+Machine+Parts/Hotpoint/WD+Dryer+Parts/1605710+-+Hotpoint+Washer+Dryer+Heater+Box.html)
4) You need a Torx scredriver/bitset to take the top of the snail off - it is fidly.
5) When you have the top off you have a fan wheel - I unscrewed the bolt (clockwise to unscrew) and cleaned all the fluff of the fan & housing & pretty much everywhere.
6) Put the fan back on not sittng against the bottow of the housing but raised slightly so that it spins.
7) Put it back all back together.
8) I bought and changed the thermistat (http://shop.ukwhitegoods.co.uk/Washing+Machine+Parts/Hotpoint/WD+Dryer+Parts/1604802+-+Hotpoint+Dryer+Thermistor.html)
9) I also changed the second thermostat which I couldn't initailly find but it turns out it the big wire on the top with the pink connection (http://shop.ukwhitegoods.co.uk/Washing+Machine+Parts/Hotpoint/WD+Dryer+Parts/C00080775+-+Indesit+%252526+Other+Washer+Dryer+Thermal+Cutout.html)
10) Put all the wire back in place
11) Lid back on - plug in and test - Fingers Crossed it works.
Cost for parts £20 and a bit of time and effort.
Pete
October 2009