I have an Astoria Argenta SAE JUN-1. It has the Sirai pressurestat. Yesterday I woke up to a dead espresso machine. Stone cold. I figured fried pressurestat, fried heating element, or blown fuse. Who knows. Turns out the pressurestat contacts ... there are three of them ... had developed carbon deposits and had lost connectivity. I took some 400 grit sand paper and polished them and the problem was solved. The Sirai unit was less than 6 months old. Has anyone else experienced this issue? The contacts honestly didn't look that dirty, but cleaning them did solve the problem. I have some old Electro Mechanical pinball games and none of them had such issues over such a short period of time with their contact switches.

In six months
yes it could develop a lot of carbon build up
it depends of course how often the pstat is cycling on and off
if the machine start cold every day or if there is a steam leak
the "outside temperature"
or simply get use a lot
don't over look also the "other" side of the pressurestat the membrane that can get affected by the minerals

Six moonths is much faster than I'd expect to see this but it does happen and to some extent it's a heat related issue. The newer La Marzocco Lineas were switched over to a matter pressure switch and a separate electromechanical switching assembly in part to address the relatively short service life of the Sirai's.

Apart from the premature carbon buildup on the contacts - which you have figured out how to address (but six months is still awfully fast!) there is a diaphragm in the Sirai the tends to dry out after a couple years and when it loses the ability to move correctly you are SOL. There is a rebuild kit available for the Sirai pressurestat but wit the limited time I have available for my very part time machine service responsibilities.... I have always just swapped out the old one for a new one and not done rebuilds.

Not sure if it makes a difference, but my machine is in my garage ... which is unheated. I've thought about a thermal blanket for the machine to keep it warm at night. The machine is left on 24x7. The Astoria was just too big to place in my home ... at least in the kitchen. There were plans to place it in the bar downstairs, but that too became problematic. The Oscar is there. A Bunn ES-1 for my office. An Astoria for the garage ...

Phaelon56 wrote:There is a rebuild kit available for the Sirai pressurestat but wit the limited time I have available for my very part time machine service responsibilities.... I have always just swapped out the old one for a new one and not done rebuilds.

I just rebuilt my Sirai. I say "rebuilt" but that sounds a heck of a lot more involved than reality. The kit contains 3 parts, the black diaphragm, a black o-ring, and a Teflon disk. Undo 4 screws, rip the parts out and drop in the new ones. The whole process takes only a few minutes and unless there's some serious scale to deal with, would be faster than taking the plumbing off, fitting a new switch, and re-wiring.

Where is a good place to find the rebuild kit? I can't seem to find it on cafeparts or espressoparts.

Thanks,
CHAD

Your live in Mead CO and have it in your garage? I use to live in Aurora, you had best hope it does not die one evening in the winter. If that boiler freezes that will be the end of the machine and in Mead, it will freeze.

To you contact issue, six months it not much. I have seen them run for years, have over a year (close to two) on my machine and it runs almost 24/7.

Again it depends hoe often a pressurestat is working
I've seen them black solid from PM visit to another ( 3 months time )
of course the customer didn't bother to mention about the hisssssssing noise for the last month or so
so again it is possible
make sure that every possible "other" issues are solved


Keep in mind that the rebuild kit will only address the membrane and not the contact
which can be clean a slightly filed down but only to the minimum
I will bring some in again in my next order from Italy but it takes forever to sell them nobody wnat's them

You can clean contacts safely with DeOxit http://www.deoxit.com/ . I find it's great for electronics and audio equipment, especially potentiometers - why not pressure contacts?

Are the rebuild diaphrams still available for Sirai pstats?

Thanks,
CHAD

Here is a source for the membrane kit http://www.coffeeparts.com/misc/pressurestats.html keep in mind the prices shown are in Aussie dollars which is worth about 9/10ths of bugger all at the moment so in US$ this place is bargain central!