The Bosch WTW863S0GB Dryer has some known problems that occur often. Here are some easy to do solutions for the problems or error codes your Bosch might be giving you.
The mains plug may not be plugged in or a program may not be selected.
The condensation container might be full.
The bulb might be burnt out.
The power supply to the dryer has been interrupted.
Automatic cleaning of the heat exchanger is in progress.
The Start/Stop button may not be selected or the door may not be closed properly.
The fluff filter might need cleaning.
The fluff filters might be clogged, or there might be insufficient air supply.
This is an indication of the buzzer setting at the end of the program.