Rancilio - Water level

The Rancilio brand originally installed sight glasses on all their commercial espresso machines. But with the latest espresso machine models this is not done anymore.

The earlier models of Rancilio had a sight glass with a diameter of 12mm and a length of 130 and of 140mm.  these sight glasses where sealed off with a flat rubber gasket. You could find these glasses on the Rancilio Z9, Rancilio Z11, Rancilio S20 and the Rancilio millennium.

With later models, like the Rancilio Epoca, Rancilio Classe 10, Rancilio Classe 8, the sight glass became from PTFE instead of from glass. The diameter of this glass is 10mm and a length of 107mm. The PTFE tube had a level regulator attached to it to measure the amount of water inside the boiler.

Note: the electronic measuring device which is installed over the PTFE sight glass on more modern Rancilio espresso machines is out of production.