Why does Bosch Logixx Dryer Condenser run for 10-20 minutes then stops, flashes the 'Start/Stop' button, inside light goes off and then after a short delay comes back on again and continues flashing?

Have you tried cleaning out the metal concertina-like element inside the bottom trap door? This clogged up caused mine to stop & also to drip some water on floor

sounds to me like a defective push start button. probably stuck on the on position

Did you check the res to see if it was full? Might be clothes inside the door and it aint shut all the way? never even seen a condenser dryer.
I have the model service manual though HERE

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follow this steps and fix it. God bless you

Timer
The timer could be the problem. To check this, turn the timer to a timed cycle say 30 minutes or so then time it. If in 30 minutes the timer hasn't moved and the dryer is still on, the timer is faulty replace it If in 30 minutes the dryer is off, the heating element is your problem

Heating Element
This is the most likely cause for some dryers timer not advancing. Some dryers have two heating elements and if one goes out the timer will not advance if you use it on an automatic cycle but you will still feel heat inside the tub. Replace it

The door is not locked properly.
Open and close the door again and press the "start reload" button (play and pause button). If necessary, open the washing machine door, remove some of the cothing items and then push the door closed again. You can also try switching the washing machine off and on again, setting the programme and then starting the programme.

You have activated the child lock, basically you have held the start button for over 3 secs. turn the dryer to the cycle you want and keep your finger on ther start button to deactivate. If this doesn't work you may have a module problem. Double check your manual for child lock info. if no module go to link and enter you Enr number.
https://portal.bsh-partner.com/portal(bD1kZSZjPTAwOQ==)/PORTALFRAME.HTM

If it is relatively new, then my advice to you, is to contact the service agents, and get it looked at under guarantee.
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Thanks.

Sounds like an electronic problem on the timer circuit board.

Most likely the heating element or a thermostat.

The Bosch Dryer has a temperature probe in the heater exit and in the exhaust area visible when you open the door. If the temperature difference between the two gets to high, the lint filter is assumed to be plugged and the alarm goes off.

It seems that the temperature probe at the heater, can end up with a faulty connection to the control panel over time due to corroded contacts or lint build up. When this happens the control panel thinks the filter is clogged and it may also not turn on the heating elements properly. Remove the back cover over the heating element (12 screws) and then remove the one screw holding the red wiring connection to the dryer body. You can then wiggle out the wiring connection and clean / unplug and replug in the connector for the sensor. (plug with two small wires only). A little hard feeding the connector back through the hole so take your time and don't damage the wires). Should all work again. May want to inspect inside the heater at same time and make sure the overheating switch is not tripped. ( press in the red button).