Why is my Zanussi dryer stopping after 4 minutes it is heating and tumbling

As you are aware, every year manufacturers of products in this country try to make their products safer, and in the case of clothes dryers, they try to make them less susceptible to fires from accumulated lint.
To that end, it is probable that your clothes dryer has accumulated lint internally, and either some fuse (or fuses) or one of the "shut-off-thermostats" is kicking in every time you start it.
Someone will need to take the whole machine apart and clean out the lint, and check the fuses and thermostats with an electrical tester.
The lint that accumulates is not caught by the lint screen, it is throughout the inside of the machine in the tubing.
God bless your efforts.
( P.S. I have taken several machines apart and found a whole shoe-box full of accumulated lint inside.)