Based on your description I'd say the issue is with the control. Bosch has had a history of this exact problem I'm about to lay out for you and this is the first thing I'd be looking for if called out to service the unit with the symptoms you've described.
As I've alluded to the issue is likely within the electronic timer/control, specifically the heater relay solder joint. ( a faulty flow switch, ntc
or heater can also cause this, but not very probable ).
My first suggestion would be calling in an authorized bosch servicer if that is an option for you and your budget
however, If you feel capable of checking this on your own, there`s a way to visually inspect the control yourself.
It will require you to remove the control from the unit and then remove the control from it`s plastic housing and look for a burnt solder contact on the printed circuit board
. This will be one of the pins from the heater relay, hence the unit sit`s and takes longer & longer to finish because it can`t heat to advance or unless the 2 buttons for "cancel" are pressed.**My Opinion - if you or someone you know is proficient at soldering, a lot of times it can be remedied by simply repairing the solder...but it has to be done well...or it will not last, although Bosch recommend`s replacing the control and I don`t pretend to speak on there behalf nor do I profess to know better. This is just my experience (it work`s) and my opinion (why buy new if one can repair ?)****Please disconnect the power or turn off the breaker before attempting any service to the dishwasher.**
If you do not feel comfortable attempting this service, call a local pro, preferably one familiar with Bosch/Thermador/Gaggenau/Siemens, to service your machine.**
Hope this answer`s your question, let me know if I can assist you further.
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