Nuova Simonelli Oscar 3-way solenoid doesn't always work

#1: Post by **apkoscar** » December 7th, 2017, 9:07 am

Hi H-Bers,

I noticed after buying a refurbished Simonelli Oscar that at the end of pulling a shot, the 3-way solenoid does not always activate to dry the puck. Am I doing something wrong to make this happen intermittently?

Thanks!

#2: Post by **kolu** » December 7th, 2017, 2:31 pm

clean it! backflush, if that doesn't help then disassemble and clean.

#3: Post by **plindy** » December 8th, 2017, 3:39 am

While not exactly helpful,
I have two well worn Oscars that show a similar malfunction:
Both with silicon group-head gaskets.
Most notably when chemical back-flushing ; tightening enough to stop leakage, will intermittently fail to exhaust thru the 3way. Slight loosening of portafilter gives exhaust.
I'am at a loss too explain, however happens less with stock size blind filter basket than with my larger custom blind filter basket.
Possibly too much headspace, between coffee and shower screen?
Will dissect the 3way shortly.
Check that the exhaust tube is not restricted
pulled the 3way, free movement of internals
replaced with another 3way = same as before
replaced poratfilter = normal 3way exhaust
you may be able to achieve normal exhaust with new grouphead gasket and / or basket...
suspect the portafilter ears mating to GH bayonet channel, as a likely candidate

#4: Post by **plindy** » December 16th, 2017, 5:14 pm

I may not be as correct as I initially thought
Backflushing with new poratfilter, same condition..
check that the exhaust of the 3way is secured to the plastic frame, behind the driptray.

Here my reasoning, the exhaust of the 3way and the brew part of the grouphead are always open to atmosphere until the brew cycle starts, the 3way closes the exhaust, and opens the path from the pump. when the 3way closes at the end of the brew cycle any restriction in the 3way or the exhaust tube greater than the resistance at the puck = no exhaust. There is always some water in the exhaust tube, if not routed and secured correctly can cause a poratfilter sneeze and or exhaust not going in the drip tray.

HTH

August 25th, 2018, 10:03 am

Hi @Plindy I'm going to take my machine apart and check the parts. Never done it before, so I'm not sure I'll be able to tell if the 3-way valve is blocked, etc. Have you had any success diagnosing this further?

#6: Post by **pebble** » August 27th, 2018, 8:10 am

I am having similar or a problem with my 3 way so interested in any findings you may have.

Do you have a video?

218 ohms resistance should be the reading of the 3 way

#7: Post by **Gionnibello** » December 2nd, 2018, 6:36 pm

Hi guys
I'm really interested in this topic. Any update on the issue? Is it the 3 way the problem or too much headroom from the shower screen?

#8: Post by **plindy** » December 3rd, 2018, 5:43 am

all things oscar

The plunger in the 3way, has an exterior spring and an interior spring. The interior spring pushes the seal on either end of the plunger, to open the brew path, and close the exhaust, or the reverse. Dependent on the solenoid compressing, or releasing the outer spring of the plunger. So the inner spring might not move freely or the seal surface is worn. I know of no source for purchase of the plunger.

HTH