rivergo1d Holding up a piece of paper between the vacuum breaker and the central fixing,
So the vacuum breaker valve routes to a connector which ultimately takes the water from the expansion valve (normal), vacuum breaker (normal), and Safety valve (not normal), and that is diverted to the drip tray. That’s why I wrote this:
MediumRoastSteam do you see steam coming out into the drip tray via the outlet at the front?
When the steam boiler reaches approx. 99C, the vacuum breaker will start hissing. Some steam, water and condensation will splutter and that will end up on the outlet at the front of the machine which then empties into the drip tray.
So, if it is the vacuum breaker that’s hissing, and this is when the machine warms up, and you see that on the outlet at the front, there’s nothing wrong with your machine.
If you see or hear the vacuum breaker hissing outside of that timeframe (i.e.: it should not happen if the boiler is fully up to temperature, as it will be closed by positive pressure), then it’s not working as intended. Regardless, you will not see condensation inside the machine, because it goes to the drip tray.
If there’s hissing on the vacuum breaker and it’s not ending on the drip tray… Then it’s either the fitting that’s not sealed properly against the boiler or it’s not the vacuum breaker. 😃