Soda fountain machines are nearly maintenance-free in the average restaurant, other than daily surface cleaning. It is a good idea to flush out the lines every month to ensure that syrup doesn't build up and cause mold growth. Lines need to be flushed before changing flavors in each station, as well as to prevent flavor mixing. Not every food service manager is aware of this procedure, but the taste quality of your soda will definitely show a difference with regular cleaning in the lines.
Unfasten the take-up line end in the line you wish to flush out. This is the end of the hose that goes into the syrup. This end of the line may be in a different room from the soda machine, so you will need two people for this task.
Place the take-up line end into a bucket that contains at least two gallons of warm water. Have the other person depress the lever that corresponds with this soda line. The machine will start pumping, drawing the clear water through the hose line. Run the entire two gallons through the line.
Mix a solution of two gallons of water and 1 cup of baking soda. Run this solution through the hose line until the bucket is empty.
Mix a sanitizing solution with two gallons of water. You can use commercial sanitizing chemicals or household bleach. Read the label to determine the proper strength for the sanitizing solution and use test strips to make sure that the solution balance has the correct pH level. The strips will come with the commercial sanitizing chemical, or you can purchase them from a restaurant supply store or your regular stock supplier. Run the two gallons of sanitizing solution through the hose line.
Run three gallons of clear water through the hose line. When all three gallons have gone through, reattach the hose line to a soda syrup container and press the lever until the soda runs correctly.