Safe back-flushing of Nuova Simonelli Oscar II

Resolve stuck valve issue with a cheap and quick home made solution. Effective back-flushing with no risk of water explosion from the brew head.

[@fAbiO-fy4bd]

i dont have this problem. i use a normal blind filter on the porta filter. and i still dont have an opv kit. you should hear the machine release the pressure when the 10 seconds are up just like you hear yours. you can feel the pressure on the porta filter. so trying to open it then is asking for trouble. just turn the pump up again and wait till your the pressure releases.

[@cvchannel959]

extraordinary 👍

[@olichu]

HI! So how did Oscar work with stuck valve issue? I Think i have the same problem, but i fright do this way >

[@romitagl]

Olii Chu it’s not extremely professional but works safely. I prefer this way rather than having the valve stuck with a big boom when removing the porta filter 😱

[@7r-q828]

do you have an opv kit and a red group head gasket??

[@baronezaza4591]

In italiano no?

[@mnabilsh]

What is the recommended procedure given by the manufacturer?

[@blizzbee]

LOL

[@beatrizbanzon6365]

Do u you remove screen on grouphead

[@romitagl]

No, I don’t

[@xiupingwu3952]

NONONONO! Ten seconds is really bad for the pump of the machine.

[@xiupingwu3952]

Generally 5 seconds is enough.

[@WrexelsWorld]

Did you do the OPV mod?

[@romitagl]

No, what’s this?

[@WrexelsWorld]

@@romitagl there is a common mod where an OPV over pressure valve is added to the Oscar to control the boiler pressure

[@romitagl]

wrexel thanks for the info, I’ve seen it now 👍

[@stumpunboxing1320]

@@romitagl Oscar 2 pressure is too high, it does not have OPV modification to limit to 9bar, so by standard it can easily go up to 15bar - so this is likely why this risk happens. Also I think they don't even mention backflushing in the user manual, probably to hide that issue. So I think this is why they didn't reply your emails. Most people install OPV kit to fix this issue. Nuova Simonelli fixed the Oscar 2 pressure in a new model called "Oscar 2 professional".