Got to say Mark1, that doesn't make a lot of sense.....
This is an extraordinarily complex machine, with full computer control. When set, the dryer may not actually cut in for several minutes. However, you should hear the fan running fairly quickly.
If the machine thinks it still has water in, the dryer will not start. This may be due to pressure switch faults or blockages in the pressure system.
The safety cut out may have been tripped. This is normally caused by blockages in the condenser system.
The computer may, as has been suggested earlier, have lost its marbles.
I would seriously suggest getting some help on this one. It's a complex appliance, with numerous possibilities as to what the fault may be. Check Repairs@ or Directories for a UKW repairer in your area.
If you wish to carry on investigating, please pull the plug first