Just a reminder, triggered by a friend bringing me his funky Silvia that'd stopped working the way it should.
If your machine has a 3-way valve (Silvia, Classic, Baby, etc) backflush daily with clear water, and at least weekly with an espresso machine-specific detergent like Joe Glo or Cafiza.
The following applies to most single boiler/dual use home machines (Gaggia, Silvia, Saeco, etc):
If your machine has a group valve, remove the shower screen and it's holder plate/dispersion disk, and the inside piece of the group valve and clean the pea valve and poke a straightened paper clip up into the hole controlled by the group valve. Scale builds up in this hole and can completely plug it. By aggressively reaming out the hole with the straightened paper clip you remove the scale that's building up before it can block the flow through the group. Too many owners of group valve equipped machines buy new pumps when flow through the valve ceases, when in fact it's a plugged group valve hole!
Machines with 3-way valves like the Silvia, Classic, and Baby, don't have group valves, so the above doesn't apply.
Removing the shower screen holder plate of a Gaggia for cleaning also prevents the buildup of scale between it & the boiler. Instances of having to use a hammer to loosen the plate on machines that are not properly maintained are not unusual.
At a minimum, descale every 3 months. Use 2 tablespoons citric acid powder per quart of water. If your machine has an adjustable OPV mounted on the boiler like the Gaggia Classic or Rancilio Silvia, be sure to use a backflush disk or blind filter to force descaling fluid back through the OPV.
A general rule of thumb for cleaning your espresso machine: If coffee touches it , clean it with a detergent. If coffee doesn't touch it, only descale it.
My mantra is, "Keep 'em clean, keep 'em working."
