I've searched around and understand soggy pucks aren't really a huge deal, but I have a question: my machine has a 3 way solenoid valve, but I only hear the "suction" sound about half the time. The other half, I hear nothing after bringing the brew lever back down. Any idea why this might be happening? The machine is pretty regularly back flushed, and all incoming water is filtered and softened beforehand.

I'm also seeing a lot of ripples in the puck surface.

It's possible that the 3 way valve is jammed with gunk (unlikely since you say you backflush regularly). Do you backflush with detergent occasionally?

Its also possible that the solenoid itself is going bad, or that the wiring or electronics that should be switching the solenoid are failing.

If you're handy with a multimeter you can try to verify that power is switching to the solenoid appropriately. If not, you may have to have a tech look at it.

If you bought from Chris Coffee, those guys can walk you through troubleshooting.

A common cause for your problem is that your exhaust valve isn't releasing completely because of wear of either the exhaust valve stem and/or the operating lever cam. Both should be inspected and replaced as necessary. In the below photo, you can see a very worn exhaust valve stem on the right. It should have looked like the "square" contact surface on the infusion valve stem on the left:



You could take a look at this thread: Quickmill Alexia: replace worn exhaust cam pin?

Randy Glass has an excellent article on the disassembly required at http://www.espressomyespresso.com/HowToE61overhaul.html

Art C

Are you using a dark roast? They tend toward soupy pucks more often. Headspace also makes a difference. You could be under dosing, so you have more water above the puck than can be evacuated by back pressure.

I would sell them to you Tom but I am in NZ. You can get them, easily available.

If you move the lever fast, you get a rapid vent and a swoosh sound. Move it a little slower and you get less of a woosh and a wet puck. If you were not venting or if you had a problem with the 3 way valve, your portafilters would explode when you took it off (search on portafilter sneeze).