Nuovo Simonelli Oscar steam valve

#1: Post by **Tatako** » August 15th, 2015, 9:57 pm

Hi,

I have a question regarding Oscar steam valve. When I shutdown the Oscar, I usually remain the valve closed so the pressure is turned to normal naturally. But for the Oscar, is it better to keep the valve open before the shutdown? Or either is ok?

Thanks.
Tatako

#2: Post by **homeburrero** » August 20th, 2015, 12:45 am

If the Anti-vac valve sticks closed, residual milk inside the wand might get sucked back in. Probably best to leave the steam valve closed when shutting down and simply let the anti-vac valve do its job.

Edit addition: Realized after posting that the stock NS Oscar does not have an anti-vac valve. Some owners add one - see Putting Nuova Simonelli Oscar on a timer and loud pop/noise at turn on

#3: Post by **gor** » August 20th, 2015, 1:04 am

Some cafes put the steam wands into jugs of water at the end of the night to soak the tips. If the rubber seal in the steam valve, is not new and has gone hard, then it is possible to get whatever is in that jug sucked up into the boiler as it cools down overnight.

Going by this logic: then if you leave the steam wand in a jug of milk and leave the steam valve open, then it would suck it up into the boiler when the machine cools down.

Otherwise, if the wand is dangling free, any residual milk in the wand should drop out of its own accord due to gravity. In this case, milk will not be sucked up.

#4: Post by **DanoM** » August 20th, 2015, 9:51 am

If you are worried about milk getting into the boiler from the steam wand then by all means keep the valve closed, BUT...

When I had an Oscar I always purged my steam wand well, and never had an issue with milk in there. If you're clean around the wand you shouldn't have issues with milk getting sucked back in.

For my Oscar, when I had it, I would always close the steam valve until steam stopped, give it a tiny turn past that point (1/8-1/4 turn) and then shut it down. When the machine and steam valve cool the machine will then allow air to pass that steam valve and become your anti-vacuum relief. In the morning when the timer kicks on the machine it will purge air & steam from the boiler through that valve until it heats up - and only a little steam passes before it's closed off again.

I used my Oscar for 1 year like that, and it was almost as good as a vacuum relief except the time I left it nearly wide open and the machine was steaming away when I woke up! Keep that tip in the tray when not in use.