Espresso Machine Leaking - Worn or Damaged Group Head Seal

The espresso machine is leaking water specifically from around the group head during brewing. This often indicates a worn, cracked, or improperly seated group head seal (also known as a gasket). Over time, the heat and pressure can degrade this seal, causing it to lose its ability to create a tight seal.

Other potential causes include improper tamping, too much coffee grounds, or using the wrong size portafilter. However, a leaking group head almost always points to the seal itself.