This is a bad thermal sensor inside.
It thinks the dryer is getting too hot so it shuts it down.
The part is not expensive and relatively easy to replace. The worst of this dis disassembly.
I will help you, do this if you're a lil handy and have a few basic hand tools.
The one you need is located on the heater box.
The best place to get that thermal and I would also replace the Thermostat in there as well so you don't have any further issue down the road is: http://www.ransomspares.co.uk/
I would call them for these two parts: 0844(###) ###-####a href="http://www.ransomspares.co.uk/" target="_blank">Home » Parts » Laundry Spares » Tumble Dryers » Siemens
I will stick with you until this is complete.
Please rate my service kindly.
Also it is the only way I am credited for my time and expertise with you.
Once you rate, I will be notified and will add your question to my priority list so you can reach me anytime until this problem is solved.
Then you can reach me by simply replying to this message anytime.
Thank you and have a great week!