Sensitivity of Sirai pressurestat adjustment.

#1: Post by **M Diddy** » July 13th, 2013, 1:36 pm

Howdy gents.

I'm trying to adjust the boiler pressure on my ECM Technika IV fitted with a Sirai P-Stat.

On my previous Cuadra, with a Mater, I would turn the pressure stat and it was a smooth turn and was easy to adjust either up or down.

On the ECM with the Sirai, I've found that the adjustment screw is much tighter and seems to "click" when I adjust it up. I completed a full turn up on the Sirai, and didn't notice a change in boiler pressure on the gauge. Is there something I'm missing here? Is there anything in particular I need to do in order to adjust?

Thanks!

#2: Post by HB » July 13th, 2013, 1:45 pm

Siria pressurestats require A LOT more turns than Mater or CEME pressurestats. One to one-half turns for 0.1 bars sounds about right. Mater pressurestats are the opposite extreme where the full range of adjustment is barely one-quarter turn.

July 13th, 2013, 1:57 pm

Thanks Dan.

What about the tension I'm feeling when turning the adjustment screw? Is that normal? It feels like I have to turn it with a bit of force and it literally "clicks" into the next position.

I've learned the hard way when I used to wrench on my VW, that if you have to force a screw/bolt to turn, you're going to break something. Want to try and avoid that on my week old machine.

#4: Post by HB » July 13th, 2013, 2:02 pm

The Sirai has a much bigger spring; it may resist a little. Sounds normal to me.

July 13th, 2013, 2:09 pm

Thanks again.

One last question. Is it ok to adjust the PStat with the machine turned on and up to temp? Or should it be powered off with 0 boiler pressure?

And one last Thank You in advance.

#6: Post by **kize** » July 13th, 2013, 3:43 pm

M Diddy wrote:One last question. Is it ok to adjust the PStat with the machine turned on and up to temp? Or should it be powered off with 0 boiler pressure?

I adjust them with the machine on and up to temp. After adjustment, wait for it to settle in before making another change.

#7: Post by **keno** » July 13th, 2013, 5:10 pm

M Diddy wrote:On the ECM with the Sirai, I've found that the adjustment screw is much tighter and seems to "click" when I adjust it up. I completed a full turn up on the Sirai, and didn't notice a change in boiler pressure on the gauge.

That's pretty much the way mine adjusts. It is a mechanical device so you need to increase the spring tension by turning it clockwise. I find it takes a few turns to make an appreciable difference.

#8: Post by **keno** » July 13th, 2013, 5:13 pm

M Diddy wrote:One last question. Is it ok to adjust the PStat with the machine turned on and up to temp? Or should it be powered off with 0 boiler pressure?

The boiler can be up to pressure, but I would definitely NOT attempt to adjust it with the machine on. Turn it off and UNPLUG it before you stick a metal screwdriver in there!