I work with a two-group La Marzocco Strada. It’s in a lab and so doesn’t experience nearly the volume of a cafe setting, although it is always on and hot. My question is, should the gaskets last longer due to it being used less? Or, since they are sitting up in the group head, they will wear down at the same rate regardless?
Yes it will last longer. You won’t need to change it until you feel like its spitting or leaking. If its not getting a lot of use, then even annual may be ok. You can peek in to see if the rubber is cracking or anything too. If it is then its time to change.
Give 'em a poke with a teaspoon handle (or anything blunt that will fit up there really). If they’re still somewhat squishy then they’re fine. If they’re solid change them.