Hot point WD 440 1400 spin ?

The dryer does not work .
I select 50% left hand control . Middle control dry selected and M selected on right hand control.
Initially when switched on the pump works . Drying high heat, Door locked, and dry lights are on. Drum turns but glass on door remains cold.
After a few minutes on/off light, drying high heat and reduces creases lights, all flash on and off drum does not turn but pump appears to be running. The machine remains like this.