Learn what to do if you're trying to use your Gaggia Classic, but it appears to be leaking around the edges of the portafilter while it's locked in the machine.
There are two common causes for leaking around the portafilter in a Gaggia Classic:
1. You're Overfilling Your Filter Basket
- Too much coffee in the filter basket will prevent you from tightening the portafilter all the way, which means the filter basket won't be able to seal properly against the gasket.
- If you think you might be overfilling your filter basket, here's how to test: fill your basket with coffee as you normally would (including tamping it down), and lock the portafilter into the machine. Then pull it out. You should just barley see the indentation of the group head screw in the flat surface of the coffee.
2. The Group Gasket Needs Replacing
Over time, the rubber in the group gasket that helps create a tight seal between the portafilter and the brew head can wear out. This can cause leaking around the portafilter basket during brewing.
If you're not overfilling your basket and your machine is still leaking around the portafilter during brewing, it's likely that you need to replace your group head gasket.
This article will walk you through how to do that: Replacing the Group Gasket.
All Other Leaks
If you've checked both of these issues but you're still finding leaks during brewing, check out this article on Troubleshooting Leaks in the Gaggia Classic.