There are a few reasons why your portafilter may not fit perfectly into the group head. In most cases, over– or under clocking (when the handle of the portafilter doesn't fit exactly at 6:00) is not a serious issue.
If you have a new machine or recently replaced your group head gasket, it's unlikely that your portafilter will lock in at exactly 6:00. This is because the group head gasket requires time to wear in before this can happen. As long as you can get the portafilter hand tight onto the machine and brew without leaking then the machine is operating properly.
If you want softer gasket for your Classic this one will allow you to turn the handle farther: Silicone Gasket
Do not use excessive force when attaching the portafilter or it can damage or break the group head gasket.
If you're having difficulty getting a solid seal on your portafilter, however, you may be experiencing one of the following problems.
Too much coffee may be dosed into the portafilter.
If there's too much coffee in the portafilter it can press into the shower screen and prevent the portafilter from attaching properly. Reduce the amount of coffee in the portafilter or test the machine with an empty portafilter. If the portafilter attaches properly then the filter basket was simply overdosed.
Check the filter baskets for dings, dents, or any sort of warping.
A filter basket that is malformed can prevent the portafilter from attaching. Try attaching the portafilter with the basket removed, or with a different basket to see if it fits on correctly.
The group gasket has slipped out of place or needs replacing.
From time to time, the group gasket may become misaligned or wear out. This video will walk you through the process of removing and replacing the gasket.
Coffee has built up in groove of the group head where the ears of the portafilter fit into.
If you've been using your machine for a while, it's likely that coffee residue has built up in the groove of the group head where the ears of the portafilter fit. You should perform regular group head maintenance to prevent this issue.
Failure of normal wear and tear items such as group gaskets, seals and shower screens are not covered under warranty. Issues due to scale build up or lack of maintenance are not covered.
If you would like to have one our skilled technicians repair your machine, click the link below.