La Cimbali Junior Espresso Help? La Cimbali M30 Bistro?

Espresso help? La Cimbali M30 Bistro? - la cimbali junior

At work we have an espresso machine, La Cimbali M30. Usually it works like a champ, but lately, when the excess water drip off, began to overflow a few times a day. I have tried bleach, to clean any obstruction to flow, but in vain. Any help to solve this problem? Everything would be great.