Hissing or water from the top of the boiler

Hissing, or water spurting inside the case

Switch off and unplug. Owner reports from older Giottos: water spurting from a valve on top of the boiler means it is overfilling, from a dirty level probe or a fill valve that will not close. A hiss after heat-up is the vacuum valve not sealing. All inside the case: dealer work.

Rocket Giotto Fast V: every job