Zanussi condenser tumble dryer - model number TC 470
Drum rotates and occasionally reverses rotation for about 5 seconds. The switch continues to rotate and cold air is expelled from the bottom. However, there is no heat.
At the back of the machine there is a plastic cover.
Remove this cover to reveal two pulley wheels.
These should be connected with a GREEN belt.
If this belt has come off (quite common) then put back on remembering to put it on with a crossover.
If the belt is broken then you will have to buy a new one.
If this belt is broken or come off then the heater will not work.