Hello,

For a long time now I'm having serious problems with my Cimbali Dosatron M30. I'm not a technical expert, so I'm probably not using the right terminology, but I'll try to explain it below:

On top of the water/steam tank there is a valve that screws into the tank. On the machine there is also a timer that turns the machine into 'sleep'-mode at night. When in the mornings the tanks warms up again, very regularly, the steam escapes from the valve with loud bangs. It looks like the steam escapes from the sides of the valve (so basically through the threads of tanks and the valve).
When I turn the machine off the explosion stop and they start again when I turn it on again. Usually after about ten times turning it on and off for some reason the steam explosion stop to occur and the tank stays on temperature.
But then the next morning the whole circus starts again... I could turn of the timer so the machine stays on 24/7, but it's a pretty old machine and I'm afraid of short-circuits and fires in my hotel...

I have tried to use different kinds of rings and gaskets to seal the valve better into the tank, but this doesn't seem to work.

Does anybody have a solution for this problem?

Thanks!

Eric Pantekoek

A photo would help a lot, but based on your description, my guess is that the vacuum breaker is failing to seal. A vacuum breaker is a valve with a weighted pin that falls when there is no boiler pressure or pushed closed when the boiler pressurizes (See What is the purpose of a vacuum breaker valve for more details). Vacuum breakers may fail to close properly due to scale buildup. Have you had the machine regularly descaled or are using a water softener?

From the description, it sounds more like the emergency pressure release opening and venting, hence the bang/explosion description. A vacuum breaker would be a slow steady hiss. What is the boiler pressure? Does the gauge climb till it goes boom then drop drastically then climb, etc... Could be a stuck pressurestat as well. If you are not failure with working on the machine, it may be best to call a service tech to work on it. If it is an over pressure issue, you may not want to use it till repaired. If the boiler were to rupture from pressure, it will kill people.