For many months now I have been searching the web, including all the coffee sites I know of, for a detailed guide for adjusting this pstat, which came as original equipment on my 1999 vintage LP Romantica Pro.. It was relatively easy to find info on the fragile toothed wheel, how it is glued at the LP factory, and how it will raise the setting when turned clockwise. But I could find nothing beyond that, not from the manufacturer's site, or from companies which sell them. Clockwise with respect to what was harder, but I did find a photo with a green arrow on it which sort of told me which way to move it; it is clockwise looking toward the diaphragm.

On this site one member indicated that there was another adjustment on this device, a Phillips type screw which he used for adjustment, but which is not easily accessible because of the way the pstat is mounted in a LP. How to Break a Glued La Pavoni Pressurestat Another site also mentioned the use of a "cross-headed eccentric peg" for dead band adjustment. http://www.spanglefish.com/avicennassol ... eid=243551

Photos on a French site showed the pstat disassembled, but only noted that the above "screw" or "eccentric peg" was removed and replaced with a bolt, which serves to hold the micro switch in place in the pstat. http://www.planetcafe.fr/forums/viewtop ... =1426#1426

I have been able to adjust the pstat with the toothed wheel to control between about 0.5 to 0.7 bar (on my LP gauge), but this was not low enough for the way I wish to operate. If there is any interest as to why, I would be happy to discuss in another thread, yet to be established.

So, I set out to examine my pstat in detail, which involved removing it for disassembly. Before doing this, so that I would not be without my machine in case I were to break or screw it up, I bought a new one of the design currently supplied by the importer, I believe it is a Ma-ter. I installed it, and it worked better than what I had, having a smaller dead band and range of about 0.5 to 0.6 bar.

Upon examination I determined that the "Phillips screw" is not a screw at all, but is a plastic post which snaps into place, securing the end of the micro switch into the pstat and precisely locating it with respect to the diaprhagm. I saw that it is very difficult to remove without damaging it, but I was able to pull it out using a small screw into its center at the wide end.

Only then did I learn that this post ("eccentric peg"), whose center section is about 1mm offset from its center line, is actually a sophisticated coarse adjustment. When it was installed I saw that it would only rotate about 20 degrees in either direction due to internal binding (this is because by turning it farther it would try to "stretch" the micro switch itself against its other mounting post). But, if after I removed it, installing it 180 degrees from its prior orientation actually moved the micro switch closer to its actuating arm by double the amount of offset, greatly lowering the basic set point.

When I reinstalled the pstat with the new pin orientation I found I had no difficulty in setting the pstat as high a range as 0.9 to 1.1 bar, but now even a setting of 0.2 to 0.4 bar is attainable. After a few trials, it is working now the way I had hoped for.
It appears to me that Signal Lux designed it with the eccentric post to be able to provide two different overall ranges using the same components, just installed differently.

See my latest post, which discusses my thoughts as to why lower temperatures can be beneficial. Not included in that discussion is the potentially longer life of elastomer components, such as piston seals, at lower temperature.

I am not sure that I have gotten the best position of the cross headed eccentric plug, as sometimes the pstat seems to hang, and turn off at a tenth of a bar or so higher, after it has warmed up (or, after two cups have been made). I may need to adjust it so that it is at its most extreme setting, to keep any sideways thrust on the micro switch to a minimum.

I have seen the posts regarding toggling, and I guess I am doing much the same thing with the pstat. However, with the pstat set as I have it, one does not have the ability to raise the pressure beyond the set point. If I wanted to steam with the nozzle rather than the cappucinatore, I don't think it would work very well.

All of my roasts are done on my Hottop, average 10 seconds into second crack. My LP Jolly grinder doesn't handle well much darker than this, nor am I convinced of my ability to always get darker roasts out of the non-manual eject early Hottop. I never see unusual flow patterns on the pucks, nor do I observe any channeling.

Thanks, Gary, for putting in the crosslinks between the 2 posts. They are right together now but most likely won't stay that way.

OldNuc wrote: switching the power off right before the pull will allow pulling back to back shots without all the thrills of overheating.
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Since the pickup tube draws water very close to the heating coils, it would be reasonable that the water would be slightly hotter at this point when the heating element is on.
My experience is also that you get somewhat cooler water into the group by ensuring the heating element is off before raising the lever for a pull.