I have a La Marzocco GS3 purchased new one year ago. Has been working well but only relatively infrequently as it is in my vacation home. Recently I have found that after pulling a shot that there remains residual pressure in the portafilter and if I remove the portafilter right after pulling the shot coffee grounds splatter everywhere. If I let it sit a few minutes before removing the portafilter it seems OK. As it is a nuisance to wait to pull another shot, and a nuisance to have a cleanup if I don't, I would appreciate any thoughts as to a remedy. Seems like there is a pressure release from the portafilter that should be activated when the paddle is off that is now not functioning. Thanks for any help you may be able to provide.

While I'm not familiar with the inner workings of a GS3- common function when pulling shots on an espresso machine involves a 3 way valve dumping excess pressure from group after shot is pulled. Sounds like your 3 way valve is either sticking or non functional. Have you or do you back flush cleaner through your group ? This helps assure that 3 way valve clean and functional.

Yes, I back flush with Cafiza about once every 60 shots or so. Thanks.

It depends which GS3 you have, the two models release the group pressure at the end of the shot in different ways.

The AV model that I'm assuming you have uses an electronic 3 way valve that is either plugged with coffee residue or the electrical solenoid on it has failed.

The MP model such as mine uses orifices in the mechanical valve that open when the paddle is returned to the off position.

You can search and find a ton of information on here in locating and inspecting your 3 way valve if you're up to the task. Otherwise it's best to have an experienced service facility repair it for you.

One last note, have you been keeping the machine clean with the proper detergent and the back flush disk? If not you may try letting it soak with a cleaning cycle and see if it clears the dried coffee residue out. Infrequent use can be harder on a machine than daily use sometimes. Always perform a cleaning when done using it for a period of time.

Thanks for the "soaking" suggestion; I did so and Voila, no splatter. Guess I need to clean more often and when I leave the machine, clean it as a last operation. Thanks for the help and replies Just pulled a great Yemen Moka Sharasi...

Glad you got it sorted!

I'll second what you already found- just cleaning a little more frequently will do the trick. If the machine is going to be sitting for a few days, I always back flush before hand..., Honestly we usually back flush every couple of days, and we only pull about 4 shots a day.

Other than that, just follow the instructions on the bottle and you should be problem free from here on out!