Bosch won't countdown to zero

Hi All. First time user.

Would appreciate your help with this problem on my Bosch SHU6805UC/U12 dishwasher.
The unit counts down to 1 and then hangs there indefinitely but keeps circulating. Upon opening the door, it can be seen that sudsy water remains filling the bottom of the tub. Also the water is hot and was being circulated but will not drain (or rinse?). There is what sounds like a rhythmic "vaccuum" noise as well, probably just the pump working.
After this was observed, I tried a different approach as per the owners manual. I turned the d/w on and then pressed the "scrub wash" and "delicate buttons" at the same time to reset the wash cycle to the beginning and drain the tub. Now all I get is "2H" in the indicator window when I try to start a new cycle. If I let it run, it appears to fill and begin the wash function. The water now only gets warm and not hot. Also, it begins to count down, at one point (45 mins? don’t remember exactly) down to 1 and won’t go to zero. Any idea if I need to perform any more specific tests? What would need repair/replacement as a result. Thanks very much for any help you can give me.
Regards,
Lou