Ah ha! The ol' not-brewing-all-of-the-water-in-the-tank trick eh! That means that your machine needs descaling -- i.e. the machine equivalent of an enema. Basically, it's a cleanser which removes any buildup of minerals that might be disrupting the water flow through the machines plumbing.
To Descale My Machine:
To keep your machine running happily, it needs a birthday every now and then. We suggest using a Maintenance Kit from our store (contains: Descaler, replacement Air Filter and Grinder Cleaner), and follow the instructions therein for the Descaler product.
Regular use of a Maintenance Kit (recommended every 30 brews) will keep your Bonaverde Berlin fighting fit!