How to Backflush the Rancilio Silvia
We've said it before and we'll say it again: Backflushing the Rancilio Silvia is an essential element of it's cleaning and maintenance routine. In fact, we say this about all machines that have a three-way solenoid/brew pressure release valve -- such as machines with the E61 brew group, the Pasquini Livia 90, Ascaso Uno Pro and Duo series or the La Spaziale Vivaldi machines, among others.
This release valve system serves two purposes: It relieves pressure in the brew head (so you don't have an exploding portafilter) and it also sucks up a little bit of water from the coffee puck (so you don't have soupy grounds). As you can imagine, this action will take water and a little bit of coffee with it each time, a residue that can build up in the system and eventually damage the machine. For a long time, Rancilio didn't recommend doing this out of concern for proper customer education and the belief that these home machines didn't get enough use to merit such maintenance. Over time, however, they have adjusted their opinion -- it is something they do recommend on their commercial machines -- and they are proponents of educating home baristas to properly care for their equipment.
While we demonstrated the procedure on the Rocket Giotto in one of our very first videos in 2008, we received many requests for demonstrations and tips on how to perform this on the Rancilio Silvia. At long last, here it is!