Somewhat new to mechanical pressurestats - new Verve machine. Used ~ 6 months everyday. Heating element failed suddenly and have successfully replaced. However, now having problem with over-pressuring of boiler. I turned the Stat down and mostly idles at 1.1-1.2 but excursions to 1.5 and occasionally higher still happen. Not sure what problem is. I notice that the hard plastic tubing leading to the pressurestat has a mixture of air (steam) and water - this seems odd to me but i have never examined before. I removed tubing and let dry in sun for a day. But air/water mixture returns as soon as machine warms up. Is this normal? There was a little greenish-blue buildup on the pressurestat intake barb and a light coating inside the barb but no evident obstruction. I'm wondering if this is even scale as I use Rpavlis water with the exception of the first month running the machine on hard water.

Edited Post
My combination pump pressure/boiler pressure gauge seemed to be working okay. I had mistaken the vacuum breaker valve for an OPV. My machine does not appear to have an OPV and I'm wondering how, when the machine now occasionally idles greater than 1.7 bar (red lines at 2 if I'm not watching), this machine is supposed to shut down the heating element. Either my gauge is incorrect or the protection failed.

Mahalo all for guidance.