My Dyson DC07 after about 5 minutes use cuts out if left for about 20 minutes it will start again why is this.

Robert Jones, June 2011

They usually have an over-heat safety cut-out strapped to the motor. Possibly the motor is getting too hot because of a fault or poor air flow - possibly the safety cut-out is defective and operating prematurely.

http://www.lmelectricalshop.co.uk/dyson-ydk-thermal-fuse-dc04-dc05-dc07-dc08-11-14-19-20-p-2924.html

Peccavi, June 2011