Removing the base and adjusting boiler pressure on a Pavoni?

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Teme

Postby Teme » Dec 11, 2005, 8:14 am

My Pavoni Pro is factory set at running a 1.1 bar boiler pressure. I can't imagine why, since this results in bitter shots even before the grouphead overheats. I would therefore like to adjust the boiler pressure to somewhere in the region of 0.8 to 0.9 bar if possible. However, I have two dilemmas:

1) This being a Millenium model Pavoni (from 2005), I think it might have the pressurestat adjustment ring glued in place by the factory to prevent owners from making any adjustments. Any tips on how to go about the adjustment if this is the case?

2) I am unable to ascertain the above because I cannot quite figure out how to remove the base. I assume it is held in place by the screw below the drip tray (pictured) and the clip at the back of the base. The main problem is the unusual design of the screw and my inability find an appropriate tool or removing it (another attempt by Pavoni to stop us from tinkering with the machine?). Any tips?

Image

Br,
Teme

User avatar
Walter

Postby Walter » Dec 11, 2005, 8:17 am

Teme wrote:2) I am unable to ascertain the above because I cannot quite figure out how to remove the base. I assume it is held in place by the screw below the drip tray (pictured) and the clip at the back of the base. The main problem is the unusual design of the screw and my inability find an appropriate tool or removing it (another attempt by Pavoni to stop us from tinkering with the machine?). Any tips?



Br,
Teme

Torx TC20 Security (with a hole in the middle) - hard to find in our neck of the woods

User avatar
Teme

Postby Teme » replying to Walter » Dec 11, 2005, 8:58 am

Thanks for the quick reply Walter. I'll see if I can get my hands onto one of those...

Br,
Teme

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Walter

Postby Walter » Dec 11, 2005, 9:13 am

You're welcome...

And, yes, indeed the manual says:

"The base-mat is fixed to the machine with a special Torx type screw, to avoid tampering with electrical parts..."

Two other links that might be useful:

http://www.lapavoni.it/PDF/RIC_Europicc...sional.pdf
http://www.pavoniexpress.com/index.html

gammeltoft

Postby gammeltoft » Dec 12, 2005, 8:16 am

Hi Teme,

I managed to undo mine using a very small flat electrical screwdriver that fits on the side of the pin in the middle of the torx. Not the most elegant solution, but handy, if you don't have the proper tool at hand. When you reinsert, I would put a bit of teflon tape, just one line, on screw. That way you'll have an effective seal against water leaking into the base.

Regarding the adjustment ring, I actually broke mine. In your case I would start by cutting it loose with a hobby knife before applying any kind of pressure. If it does brak, don't despair, the adjustment ring can be replicated by a bit of thin metal wire spun around tightly 6-7 times. That works for me anyway. The pressurestat used in the Pavoni is quite finicky and strange compared to those used in most other home levers. In e.g. the elektra and riviera, there is a much more solid construction for adjusting. I always had a feeling that the Pavoni, due to its open design and plastic parts would be more prone to travel as time goes along.



Best of luck

Thomas

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cannonfodder
Team HB

Postby cannonfodder » Dec 12, 2005, 12:13 pm

Morning Teme. Take a look at my thread Digital temperature controller on a lever machine. I have photos of the bottom of the machine. I completely bypassed the pstat and put in an adjustable temperature controller.

The results were a bit mixed but I do get better shots now. The problem with the Pavoni type machines is that they require at least .5 bar to operate, that is around 228F at my altitude.
Dave Stephens

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Teme

Postby Teme » Dec 12, 2005, 5:45 pm

I did find myself a Torx today and took the base of the off. And what do you know, the adjustment ring on the pressurestat is glued on as I suspected (the white blob shown by the red arrow).
Image

Thomas, I thanks for the tips. I'll try and take the pressurestat off and get as much of the glue off before applying any pressure. I have to agree regarding the construction of the Pavoni - it looks like they are cutting too many corners to save costs - the all plastic boiler cap vs the brass threads on the older ones, the plastic p-stat vs the older more solid ones I've seen pictures of, the thin gauge metal on the base vs the thicker one on the old Pavonis etc.

David, I noted your project earlier. Very interesting, thanks. However, I think I'll stick to the fully manual approach of the Pavoni without external components. It might be interesting to try an alternative, higher quality p-stat, though...

Br,
Teme

User avatar
cannonfodder
Team HB

Postby cannonfodder » Dec 12, 2005, 11:03 pm

My results were mixed with the controller. I left the OEM Pstat on the machine so if I change my mind I can switch back. IMHO, too many gizmos ruin the classic lines of these machines. It was a fun tinkering project though.
Dave Stephens

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Teme

Postby Teme » Dec 13, 2005, 4:55 pm

I managed to scratch off most of the glue with a sharp, pointy knife today. I did my best to avoid damaging the (plastic) threads on the pressurestat. This seemed to work as the adjustment ring is still in one piece, it now moves and I did not have to apply too much force to move it. Great - almost. The ring only moves a couple of full turns worth and then gets stuck again. There is room for further turns in the threads in the direction I am turning (to release pressure on the prongs of the p-stat) - and I do not believe the threads (at least not on the ring) are damaged. What gives? The lowest I can currently go is just under 1 bar max pressure (with approximately 0.9 bar minimum). I am calling it a night but will check in the morning if this has any results in terms of the shot quality and if the adjustment ring turn further when the machine has cooled down...

Br,
Teme

User avatar
dane1234

Postby dane1234 » Dec 27, 2005, 2:31 am

December 26, 2005

Teme:

For information on my experience with the pressurestat switch of my La Pavoni PC16,
see http://community.webshots.com/user/dane1234, then the "La Pavoni" folder.

Regards,
Dane E. Ericksen
LMWDP #57
Sonoma, CA