Your group gasket and shower screen are the first parts of your machine that touch your coffee. Both wear out, both are inexpensive, and swapping them is one of the most satisfying fixes you can do at home.
It's also a job plenty of people put off longer than they should. The good news is that on most machines you can change both in one sitting with basic tools. We'll cover how to tell when they're due, how to find the right parts, and how to make the swap without scratching up your group.
In This Article
What the Gasket and Shower Screen Do
The group gasket is the rubber or silicone ring set into the underside of the group head. When you lock in the portafilter, the rim of the basket presses up against it and forms a seal, so brew water has nowhere to go but through the coffee.
The shower screen sits inside the gasket. It's a fine mesh or perforated metal disc that breaks the stream of water from the group into an even shower across the whole puck. An even shower is what lets the coffee wet and extract uniformly.
Heat, pressure, and coffee oils work on both parts every day. The gasket gradually hardens and loses its spring, and the screen collects oils and fines that block some of its holes. Neither fails all at once, which is why the signs are easy to miss.
Signs Your Gasket Is Worn
The most common sign is water or coffee escaping around the edge of the portafilter during a shot. Drips running down the outside of the portafilter, or grounds collecting on the rim, mean the seal is no longer holding. Our guide to leaking from the group head covers the other possible causes.
Handle position is the other giveaway. As a gasket hardens and compresses, the portafilter has to rotate further to make a seal. A handle that now locks in noticeably further to the right than it used to, or one you have to push harder to seal, points to a gasket that's on its way out.
You can also check it directly. With the machine off and cool, look at the gasket and press it with a fingernail. A healthy gasket is pliable and springs back. A worn one feels hard, looks shiny or cracked, or has pieces missing around the edge.
How often a gasket needs replacing depends on how much you use the machine and what it's made from, so follow the interval in your manual and let these signs tell you if it's due sooner. Our espresso machine maintenance schedule puts it in context with your other routine tasks.
Signs Your Shower Screen Needs Attention
Run water through the group with no portafilter in and watch the pattern. A healthy screen produces an even shower across its whole face. Dry patches, streams that shoot off at an angle, or one area flowing much harder than the rest all mean some holes are blocked.
A blocked screen often shows up in the cup and the puck before you notice it at the group. Uneven extraction, a puck with a wet or cratered spot in the same place every time, and shots that channel even with good prep can all point to the screen. Our article on channeling covers how to read a puck.
Many blocked screens can be cleaned rather than replaced. A screen that's bent, has torn mesh, or stays blocked after a soak is due for replacement.
Finding the Right Parts
Gaskets vary in diameter, thickness, and profile from one group design to the next, and even within a single brand. A gasket that's slightly too thick will make the portafilter hard to lock in, and one that's too thin will leak. Screens vary in diameter, mounting style, and hole pattern.
The safest route is to search by your machine's make and model. Your manual usually lists part numbers, and our group gasket and shower screen collections are organized to make matching easier. For example, the Rancilio group head gasket fits Rancilio's home group. Our team is happy to help with this, too. Give us a call or start a live chat with your model (or the part number from your manual) and we'll help you match it before you order.
Some groups accept both rubber and silicone gaskets. Silicone stays pliable longer and many people find it easier to lock against, while rubber is the traditional choice and often what the machine shipped with. Either works when it's the correct size.
Before You Start
Work on a cold machine. Turn the machine off, unplug it, and let it cool completely before you start. The group and screen hold heat long after the machine is switched off, and some machines keep the boiler under pressure for a while after shutdown.
Gather a small flat-head screwdriver or a dedicated gasket pick, a screwdriver for machines with a screw-mounted screen, a towel to protect the drip tray area, and the new parts. A group head brush and some Cafiza are useful for cleaning while everything is apart.
Remove the drip tray and lay the towel underneath. Trust us, a tiny screw rolling into the back of the machine isn't how you want to spend your afternoon.
Removing the Screen and Old Gasket
Screen Held by a Screw
On many machines, including the Rancilio Silvia, a center screw holds the shower screen and sometimes a metal dispersion plate behind it. Remove the screw, keeping hold of the screen so it doesn't drop, and note the order of any plates as they come out. With the screen out, the gasket is exposed and can be pried free.
Screen Held by the Gasket
On E61 groups and many similar designs, the gasket itself holds the screen in place. Here you remove the gasket first and the screen comes out with it or just after.
Brendan from our crew walks through the whole swap on an E61 group in the video below, from prying out the old gasket to seating the new one. He's using our E61 tune-up kit, which bundles the gasket and screen together. Diletta owners can grab the Diletta E61 Group Tune-Up Kit for the Alto, Bello, and Bello+.
Getting the Old Gasket Out
Work the tip of the pick or screwdriver between the gasket and the group wall, and lever it down a little at a time, moving around the circle. Angle the tool toward the gasket rather than the metal so you don't scratch the group, since a scored sealing surface can leak even with a new gasket.
An old gasket that has hardened in place can be stubborn. It may come out in pieces, which is fine. Patience pays off here! Take your time and make sure you remove every fragment, because even a small piece left in the channel will stop the new one from seating flat.
Cleaning and Installing the New Parts
With everything out, clean the gasket channel and the face of the group with your brush and a damp cloth. Coffee residue packed into the channel is common and needs to come out before the new gasket goes in.
Reusing your screen or dispersion plate is fine. Soak them in a Cafiza solution to dissolve built-up oils, then rinse well. Our guide to which coffee cleaner to use explains why Cafiza is the right product for coffee residue.
Fit the screen and any plates in the order they came out. On screw-mounted screens, snug the screw firmly without forcing it. On gasket-retained designs, hold the screen in place as you fit the gasket.
Press the new gasket up into the channel by hand, working evenly around the circle. Many gaskets have one beveled or tapered edge, and on most groups that edge faces up into the group, but check your manual or the part listing for your machine. Once it's started, lock an empty portafilter into the group and rotate it gently to seat the gasket the rest of the way.
Reassemble, refill, and turn the machine on. Once it's up to temperature, run water through the group to rinse, then pull a test shot or two and watch the portafilter rim for leaks. A new gasket can feel stiff at first and usually softens slightly as it heats up over the first few days of use.
This is also a natural moment to backflush on machines that support it, and to clean your portafilter and baskets.
Handle Still Swinging Too Far?
A new gasket should bring the portafilter handle back to roughly where it locked in when the machine was new. Beyond that point, the usual suspects are the locking ears on the portafilter or the lugs inside the group, both of which wear over years of use. Some groups accept a slightly thicker gasket to make up the difference, while others call for a new portafilter or group parts. On E61 groups, that usually means stepping up from an 8mm to an 8.5mm gasket, which is exactly why our E61 tune-up kit also comes in an 8.5mm version.
A portafilter that won't lock in at all after the swap usually means the gasket is the wrong thickness or isn't fully seated. Our guide to a portafilter that won't lock in walks through that. Our marketing blog also has a short video on gaskets and portafilter wear that shows the issue.
If your machine is still under warranty, check with us before working on it. You can reach our service team through our contact page, by phone at 866-372-4734, or by email at support@seattlecoffeegear.com.
Frequently Asked Questions
How often should I replace my group gasket?
Follow the interval in your machine's manual, and replace it sooner when you see leaks around the portafilter, the handle locking further to the right than it used to, or a gasket that feels hard or looks cracked.
Should I replace the shower screen at the same time?
It's a good time to inspect it, since the gasket often has to come out to reach it anyway. A screen that's just blocked with oils can be cleaned. One that's bent, torn, or still blocked after a soak should be replaced.
Which way does a group gasket go in?
On many gaskets the beveled or tapered edge faces up into the group, but designs vary. Check your manual or the part listing for your model before fitting it.
Rubber or silicone gasket?
Both work when they are the correct size for your group. Silicone stays flexible longer and many users find it easier to lock against. Rubber is the traditional option.
Why does my new gasket make the portafilter hard to lock in?
New gaskets are stiffer and often soften a little with heat over the first few days. A portafilter that's very hard to lock in is worth a second look, so confirm you have the right thickness for your group and that it's fully seated.
Gaskets, Screens, and the Tools to Fit Them
Model-matched group gaskets, shower screens, and cleaning supplies, plus a team that can confirm the right part for your machine.
Shop Group Gaskets Shop Shower Screens