Acid/Bicarb or UF pump Stuck

The main times that we've had stuck pumps is when the machine is first turned on. We determined in those instances that citric acid wasn't being completely rinsed out due to the long coil acid lines. Adding 5 minutes to the default rinse time solved those.

The times where a pump would stick in the middle of something has been on much older machines and the motor was going bad. On rare occasions, we have had something wrong with the piston pump itself get stuck. In those instances you could hear and see the pump/motor vibrating.

You say its "random" but is it ever always the UF pump on machine "A" but always the acid pump on machine "B".?

You said in another post that your machines are just out of their 6 month warranty. I would double-check that. I thought Braun typically gave a 12 month warranty.