A few threads ago I mentioned having pstat and chrome issues with a new Cremina SL. After having both sorted, my recently replaced second pressure stat has again started occasionally running up past 1.5 bar. This one lasted about a month while the first one gave up the ghost after two months. I use rPavlis water so I know it's not scale. My current theory is that the higher pressure setting required of this machine (1.1 to 1.3) as compared with the regular Cremina (.8 to 1) is possibly to blame. The mater in this machine is specked at 0.5 to 1.5 so the SL operates at the higher end. I'm wondering if folks on this forum that know more than me could offer some advice here. How can I stop having to keep replacing these pressure stats? And do you think this is perhaps some kind of a design flaw as it operates at a higher boiler pressure ?

1.1-1.3 bar is a pretty normal pressure setting for a spring lever p'stat. I can't see that causing your problems. I use a Mater p'stat/SSR combo to control the steam boiler pressure in my pump machine. The Mater is spec'd for 0.5-1.5 bar like yours but it's been set to 2.1 bar since 2015 with no problems.

Thanks John,

If it's not water/scale and it's not out of spec then I wonder what's causing this? Maybe just two bad pstats from the same production run plus bad luck

Have you contacted Cerini about the issue?

How far past 1.5 bar is it going?

Just slightly past 1.5 and only occasionally. I'll contact Olympia to see if they have any ideas. I purchased from a vendor in Canada who has been very helpful. Pretty sure that the issue lies with the mater and not the machine now. It's just sticky.

Just another data point. My Olympia Maximatic runs around 1.1bar and I assume it's the same pressure stat. Going on 18 months now with no issues. Fingers crossed.

My SL went on a runaway some time last year pushing toward 2 bar. What I did when I had a Bezzera Family with its ancient pstat was to pick up the corner of the machine and drop it - not much but just a little.. I did the same to the SL and then when it ran away again, and I haven't had any problems since.

I'm sure there is a better way to help with pstat stickiness, but this was the (foolish) way I approached it...

I have my Cremina (it is not an SL) set on 0.8 to 0.9 bar. I keep a close eye on it, as I like to start my pulls at 0.9 for uniformity. I have seen the pressure go up to about 1.0 occasionally, perhaps once every couple of weeks. It is typically soon after it reaches the set pressure but before the group is entirely heated. It happens so infrequently that I haven't felt the need to bother with it. I suppose if it happened more often I would change the pressurestat, and I keep a spare one on hand just in case.

My previous Cremina, which I bought new in 2017 and used for about four years, did the same thing. Once it went up to about 1.05, and I thought it was failing, but before I could reach the off button it cycled, returned to the usual pressure setting, and never went that high again that I noticed.

redpig wrote:My SL went on a runaway some time last year pushing toward 2 bar. What I did when I had a Bezzera Family with its ancient pstat was to pick up the corner of the machine and drop it - not much but just a little.. I did the same to the SL and then when it ran away again, and I haven't had any problems since.

I'm sure there is a better way to help with pstat stickiness, but this was the (foolish) way I approached it...

Ha! That reminds me my father instructing me to slap the side of our black and white picture tube television many decades ago to stop the picture from rolling when the vertical hold knob was at its limit. It worked for a time, but eventually I'm sure it probably caused more trouble than it cured. It was when my father took it for repair that we finally got our first color console television.