If this is happening frequently, then you need a support stuff. The support stuff will spend those 3 hours to get the actually problem and explain it to you in 10 minutes at the end of the day.
If you want to focus, and your work is programming then you should delegate support to someone else. Probably a knowledgeable person about the software and some programming/technical skills to solve trivial problems.
If you want to focus, and your work is programming then you should delegate support to someone else. Probably a knowledgeable person about the software and some programming/technical skills to solve trivial problems.