Hello everyone,

About a year ago I purchased a used Nuova Simonelli Oscar which was marketed as "rarely used, only a year old".
It has the old p-stat (It says Campini).
There's a leak right under the p-stat. (Photo)


I wanted to take the p-stat off, have a look at it and probably replace it since as I understand the non Sirai ones are quite ancient. I can't seem to unscrew the the pressure-stat alone. When I try to grab the thread under the p-stat (Under the "1" written on the ring) what gets unscrewed is the whole assembly with the OPV and the pipe that goes into the boiler.
Is it possible that it's just stuck in there and I need to grab the pipe above the OPV and hold it in place while I try to unscrew the p-stat?
Or is the plastic part (the actual p-stat) detachable without the ring under it?

Is replacing the p-stat a good idea or is there a seal I can replace more easily (and cheaper).

Am I in over my head and just talking rubbish?

Thanks in advance!

If you can remove the entire assembly from the boiler then go ahead - it will make taking the pressurestat off easier. You can get to the parts easier - then reassemble and re attach after figuring out how to stop the leak.

I wouldn't consider replacing the pressurestat unless it isn't working - just old isn't the same as broken.

It looks like the leak cannot be fixed, it's right under the plastic part above the copper and there's no way to seal it better.
I guess I'll go chasing local dealers for espresso machine parts, I don't know if there are any:-\

Thanks for the help!

My Oscar uses a Ma-ter that looks like this - Probably should make sure for yours but mine is 1/4th inch:

http://www.espressoparts.com/MZ_L271

My father took one look at it and said he has no problem fixing the leak using some resistant paste, I'll see how that goes before I go on my wild chase.

I understand that it's possible to use a few p-stat models. What is the difference between them? Is it worth paying the extra 50-60$ to get a Sirai P-stat or is the Ma-ter good enough?

Thanks!

Sirai pressurestats are far more robust than the Ma-ter or Jager p-stats. I had to replace my first Ma-ter p-state after a couple of years, whereas Sirais can last for many years. I believe the Sirais can also be worked on and rebuilt if they start to have problems, whereas the others just need to be thrown away and replaced. So yes, I would say it's worth the extra money for a Sirai. I'd get one myself, except there isn't enough room in the machine for it.

I understand that the Sirai p-stats are standard in the new Oscar, could there be a problem fitting it into an old machine?

I doubt there'd be a problem, since the case is the same size in both. Sirai p-stats are much larger than Ma-ters or Jagers, so they don't fit in some prosumer machines. But if one can fit in the new Oscar, I don't see why it wouldn't fit in the older ones as well.

However, I haven't looked at one in person, so don't rely on my opinion here. You might want to check and see how much room there is around your current p-stat. You'll need several inches of space in all directions for a Sirai to fit.

Just FYI, according to what the seller told you your machine is only about 2 years old. I bought a new Oscar 3 years ago and it came with a Sirai. I'm in Canada however and I seem to recall something about the Sirai's being implemented earlier in North America.

..It also could have been old stock when the previous owner bought it.

Here is the way the Jaeger is mounted in the current Vibiemme Double Domobar. "Floating" a different pressurestat on copper pipe using compression fittings as seen above should give you a lot of options. The "empty" connections is not used and protected from shorting from the factory as seen here. (I assume it powers a "normally open" connection, powered when pressure is reached maybe?).