Steam leaking from top of Nuova Simonelli Oscar!

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
LatteLarry
Posts: 20
Joined: 11 years ago

#1: Post by LatteLarry »

This morning, I suddenly lost pressure while pulling a shot and had steam rising out of the top vents at the same time. I took the top off and turned it on to see where the steam was coming from.

I'm guessing the image below is of the pressurestat? When I put pressure to the portafilter, this is where I'm getting water. I'm feeling fortunate that daily use of the machine for six years has only had minor repairs needed...gasket on boiler and steam want replacement.

If this is the pressure stat, any references you can share for removing the pump and replacing it will be most appreciated!

Thanks!



sikijou
Posts: 20
Joined: 9 years ago

#2: Post by sikijou »

I believe that is boiler safety valve, but the black box that has sirai engrave is a pressurestat

samuellaw178
Supporter ♡
Posts: 2483
Joined: 13 years ago

#3: Post by samuellaw178 »

Oops. If you get water spitting out of the boiler safety valve with pressure in the portafilter, you're almost sure to have a split hx..not a minor issue..time to think about an upgrade. :?

LukeFlynn
Posts: 1293
Joined: 10 years ago

#4: Post by LukeFlynn »

This is somewhat unrelated, but in agreement with Sam.. I think an upgrade is in your near future.. I upgraded from an Oscar to a Breville Dual Boiler, couldn't be happier.

LatteLarry (original poster)
Posts: 20
Joined: 11 years ago

#5: Post by LatteLarry (original poster) »

OK, learned that is the boiler safety valve. Anything I can check before jumping to an upgrade?

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drgary
Team HB
Posts: 14347
Joined: 14 years ago

#6: Post by drgary »

Thorough descaling, maybe, using 50/50 white vinegar and water. Your machine could be overheating due to scale buildup in the pressurestat and on the heating element. If the pressurestat fails to open the circuit it can be because the passage to the boiler is clogged. Or your pressurestat may need a rebuild. There are rebuild kits for sirai pressurestats. Or you might swap to previously unused contacts on the pressurestat if the old ones are worn. Check the connections to contacts too. Those are just a few ideas. Be careful not to overheat your machine or let it run dry. I hope it's not a split HX, which could be replaced.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

LatteLarry (original poster)
Posts: 20
Joined: 11 years ago

#7: Post by LatteLarry (original poster) »

Yes, miss my coffee. My father passed away so I'll be tinkering with my machine after this.

How do I tell if the HX is split?

Thanks!

LatteLarry (original poster)
Posts: 20
Joined: 11 years ago

#8: Post by LatteLarry (original poster) »

Yes, miss my coffee. I'm now making Moka pot Americano's.

My father passed away so I'll be tinkering with my machine after this.

How do I tell if the HX is split?

Thanks!

samuellaw178
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Joined: 13 years ago

#9: Post by samuellaw178 »

Sorry to hear that... my deepest condolences...

To confirm a split hx, pull a blank shot with blind filter (as if you're doing back flush). Cold machine is fine for the test. If the safety valve blows with that act(seems to be what I understood from your description), then it's 100% a split hx.

Here's a diagram how the system works. Normally, the boiler pressure(1 bar) is isolated from the hx circuit (9bar). If pulling the shot triggers the safety valve, it means the 9 bar pressure somehow gets into the boiler. The only explanation is a split/leaked hx.