Hello,

This is the second time I've descaled my Sama Lusso in a month (Club?), I use only the best brand spring water I could find around. I'm trying to reduce the pressure a bit to the spot everyone suggested here (1,1bar?), curious how it taste!. No matter what I do, descaling or set the p-stat at the lowest setting, still its needle stop at little over 1,5. This picture I took about a month ago or so, now it's even gone higher a bit maybe 1,6 or 7.

Would you suggest to change the p-stat? or is it something to do with the gauge? And btw, the p-stat is SOPAC type "PS", and it has one free lug numbered "2". If look at the switching schematic on it, the wire is connected to 1. When I got it, the cable was not connected to either lug (1 or 2) so it must be disconnected during a long way shipping from Holland. I was just guessing and get it connected to 1 and the machine heated up. Could this be the issue? I have not tried to connected to 2 tho.

Thank you for the advice.

BTW, If even you would suggest to let alone the machine, I would too, as I still enjoy my everyday espresso, it just to fill the curiosity.

It looks like an old P-stat, and could be bad. A new one would probably not be too expensive. I like to keep the pressure around 1.0 bar or a little less. This keeps the water temperature a little lower, and I like the taste of the espresso better. If your espresso tastes good to you already, you may not need to lower the pressure.

If the pressurestat is not working well, be sure that the pressure relief valve is working, so the pressure does not go too high.

Thanks!

Should I increase the p-stat once to see if the pressure relief valve is working? To what bar max I should switch it off in case it doesn't work at all? in other words at what bar the tank can hold the pressure (far!) before it goes kaboom! I usually leave the machine on whole day, it switched off when it needs a refill or when I remember and when we have a blackout (which is a routine at where I'm from ), since you remind me this, I will switch it off every after making espresso from now on. ayy...

novyan wrote:Should I increase the p-stat once to see if the pressure relief valve is working?

Rather than raise the p-stat, the safer approach would be to adjust the relief valve to "crack" at a lower pressure, so steam is released. You want to make sure the high pressure relief is not stuck shut with mineral deposits.

I've been looking for information on the SOPAC pstats and, so far, the only ones I've found that look like yours have a minimum pressure of 1.5.

http://www.all-sewing.com/catalogue/irontex/213.htm

EDIT: Here are some that go lower, e.g. the 14. and 15. series.

http://stiroservice.com/c_prodotti.asp?textfield=sopac

I have what appears to be the same SOPAC pressurestat on a cousin of the Sama Lusso, a 1970's Bezzera lever. It has "8 - 76" stamped on it, so I suspect it is from 1976. And it is still working fine.

Here's a picture. You can see that, like yours, the contact 2 is not used:

timo, thanks appreciate your advice!

I know now there's nothing wrong with the p-stat, it just doesn't go below 1,5 bar! great NFO!

timo888 wrote:Rather than raise the p-stat, the safer approach would be to adjust the relief valve to "crack" at a lower pressure, so steam is released. You want to make sure the high pressure relief is not stuck shut with mineral deposits.

Yes I do really want to make sure that doesn't happen here, so need to know at what bar I'd expect it to crack (1,9 bar? or should I adjust it lower if it go over 2?) if the p-stat ever fail to switch off in the future. I think I read somewhere the tank should stand 2 bar pressure. And my understanding is, the only way to see if relief valve is working or crack at certain pressure is to raise the pressure switch adjustment and watch. right or wrong?

Again thanks for the link, I will order the PS 15.01 (0.9-1.7) looks just what I wanted, I hope they do world wide shipping.

@JB130,
Thanks, yeah looks like the same one. So I recon yours doesn't go bellow 1,5 bar too.

O looking at the switch schematic, now I understand that number 2 is live when 1 is cut. this could be useful

If the safety valve is adjustable: you can leave the pressurestat where it is, allow the machine to reach its 1.5+ bar, and then back off the safety valve until it cracks and emits steam. Then you would know that it cracks at 1.5 bar. This is for the Cremina but if the valve is the same type, it may help:

Olympia Cremina Offical Factory Setup Information

novyan wrote:Thanks, yeah looks like the same one. So I recon yours doesn't go bellow 1,5 bar too.

I have only had this machine for a week and have not had a chance to try adjusting the pstat. But as it's set right now, the heating element kicks on at 0.8 bar, and it turns off at 1.5 bar. Quite a wide range!

novyan wrote: I will order the PS 15.01 (0.9-1.7) looks just what I wanted, I hope they do world wide shipping.

Do you think you might already own the 15.01 model? Mine is stamped 1501, which makes me think that I might:

A ha thank you timo!
At the link you sent me, they have this this SOPAC SP 1401 (0.2-0.9), does it mean the element switch on at 0.2bar and switch it off at 0.9? Or can be set to switch off at any pressure between 0.2-0.9?

@JB130,
:O mine has nothing stamped on it, I remove the housing and really use a magnifier to see if there is any trace of a dried ink or something on that space. There's nothing there . Btw, do you have a pic of your bezzera? Heard about it, but never seen one.
You said,

the heating element kicks on at 0.8 bar, and it turns off at 1.5 bar. Quite a wide range!

wide rage means a good or bad?

The numbers represent the minimum and maximum pressures under which the switch can function, not the on/off settings.

Many home-baristas would consider it a virtue in a pressurestat that it have a narrow dead-band, i.e. on at 1.0 and off at 1.1, because the pressure (->temperature) doesn't wander far. However, it is possible to make a virtue of a wide dead-band. If the switch turns the heating element on when the boiler pressure drops below .8 and turns it off when the boiler reaches 1.2, you have a way to pull shots at different temperatures -- a rather crude method, true. If you want higher temperature, pull when the water's at its hottest; for a cooler shot, pull just before the element kicks back on again.

novyan wrote: Btw, do you have a pic of your bezzera? Heard about it, but never seen one.

You can see a picture here.

timo888 wrote:The numbers represent the minimum and maximum pressures under which the switch can function, not the on/off settings.

Thanks, so this answers the wonder in mind about the p-stat model on this Sama. Look back to the link you gave, unless something wrong with it, the p-stat is 16.01 (1,5-2,8bar).

timo888 wrote:Many home-baristas would consider it a virtue in a pressurestat that it have a narrow dead-band

Any brand or link to this p-stat?

@JB130
WOW!!! Sweeet!!!

novyan wrote:Look back to the link you gave, unless something wrong with it, the p-stat is 16.01 (1,5-2,8bar).

The range of the 16.01 is too high. Since you cannot get your machine to go below 1.5, you might have the 16.01. With the 16.01, the minimum pressure is 1.5 bars, but that is really the maximum pressure you'd ever want to use. You want to shift the range lower. A pstat that supported a range of 0.5 to 1.5 would let you try lower temperatures, but the 15.01 model at 0.9-1.7 would also be OK.

Thank you timo!

Yes I definitely think the p-stat is the 16.01

What p-stat to have range 0.5-1.5?
And btw, do you happen to ever play with this in the pic

Perhaps the pressurestat that fits the Ponte Vecchio Lusso will fit your machine?

In my Ponte Vecchio Lusso I have a Mater XP110 pressurestat, which operates between .5 bar and 1.5 bar, which is a very thorough range. Before I had a Mater XP110 (same number) that operates between 1 bar and 2.5 bar. I much prefer the lower range, and keep mine set to cycle between a low of .5 and a high of .8.

I have never seen the SOPAC pstats in person, so I haven't ever adjusted that particular screw. The adjustment is within the minimum/maximum range.

Search this website for "adjust pstat" and you'll have enough reading to last the rest of the year.

I don't know what brands are readily available to you, but here in the U.S., MATER and CEME are the two main players in the domestic class espresso machine aftermarket.

Thank you timo!

Will find out what's that thing for, it could be the deadband adjustment.

Will put Ma-ter xp110 into consideration, thanks grong!