Why Is My Espresso Machine Leaking from the Group Head?

Water dripping or leaking from the group head during or after a shot is almost always one of a few well-understood issues, and most are fixable at home.

If water is dripping from your group head during a shot, after a shot, or whenever the machine is on, there's a good chance you already know the fix once you identify which component is involved.

Worn Group Head Gasket

The group head gasket is a rubber or silicone ring that creates the seal between the portafilter and the machine. It takes a beating every time you pull a shot, cycling through intense heat and 9 bars of pressure repeatedly. Over time it compresses, dries out, and loses its ability to seal properly. A leak around the group during extraction is the most common symptom.

Another sign is a portafilter that now locks in past the 6 o'clock position. A fresh gasket sits tall and seats the portafilter earlier in its rotation. As the gasket flattens, the portafilter has to travel further before it makes a seal. If yours has crept past 6 o'clock, the gasket is almost certainly the culprit.

Rubber vs silicone. Stock gaskets on most machines are rubber. Silicone gaskets are available for many popular models and tend to last longer and stay more flexible over time, which makes them easier to remove when it's eventually time to replace them again. If your machine supports one, it's worth considering. Check the group gaskets collection for what's available for your machine.

Replacing the gasket. Unplug the machine and let it cool fully. Remove the shower screen (usually one center screw), then work the old gasket out of its groove. A flathead screwdriver can do this on most machines, though go carefully to avoid scratching the group head surface. Press the new gasket into place by hand and finish seating it by locking in the portafilter and pressing firmly a few times. Reinstall the shower screen. Gaskets are machine-specific in size, typically $5 to $15, and should be replaced about once a year as standard maintenance.

Dirty or Clogged Shower Screen

The shower screen sits directly above where the portafilter locks in. Coffee oils and fine grounds build up on and around it with every shot. When it gets sufficiently blocked, water can find alternate paths, including back around the gasket seal.

Remove the shower screen, soak it in Cafiza for 15 to 20 minutes, and scrub it clean with a group head brush. This should be part of your monthly maintenance routine regardless of whether you're experiencing leaks.

Portafilter Basket Damage

This one is easy to overlook. If your portafilter basket has small dents or dings around its rim from years of knocking out pucks, the basket edge may no longer make clean contact with the gasket under pressure. Water will find those gaps and leak out, even with a new gasket installed.

Check the rim of your basket closely. If it's visibly dented or deformed, a replacement portafilter basket is a cheap fix that's often overlooked when chasing a persistent leak.

Stuck or Failing Three-Way Solenoid Valve

Machines with a three-way solenoid valve use it to relieve pressure after a shot. If the solenoid sticks open, water drips continuously from the group between shots. If it sticks closed, you'll get a pressurized burst when you remove the portafilter.

Solenoid issues are not user-serviceable on most machines and typically require professional repair or component replacement.

What to Try First

Start with the simplest fix: clean the shower screen and group head thoroughly with Cafiza and a group head brush. If the leak continues, inspect the gasket. If it looks flat, cracked, or shiny, replace it. While you're at it, check the basket rim for damage. Only after both have been ruled out should you suspect a solenoid issue.

Our repair team services many espresso machine brands. Learn more about our repair services if you need to go further.