Why does my Hotpoint TDL30 dryer decide to run at a slow speed?

My Hotpoint Aquarius TDL30P dryer should run clockwise then anti-clockwise but lately, instead of reversing after running for a few minutes in one direction, will decide to continue to run in the same direction but at a lower speed. The heating element will then start to get too hot as the fan is also running slowly. Any ideas on what's gone wrong and how to fix it?
Andy Draper, April 2009


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