Greetings....I am the proud owner of an old Nuova Simonelli Personal 1. This morning the machine, named Sonia, had no steam pressure. I trouble-shooted the power to the pressure stat and it is getting power in. My OPV is spitting steam water...which makes me believe that she is getting power to the heating coil but the pstat is not signaling to stop heating. Am I correct to assume the pstat is a goner?....please help.

Hello....Just wondering....how do you know your pressurestat needs to be replaced?....My machine, a 25 years old Nuova Simonelli Personal 1, is not getting any steam pressure and I am considering replacing the Sirai pstat.

I merged your two threads into one.

When a pressurestat fails, it either fails closed because the contacts weld themselves together (symptom: machine overheats until safety valve releases steam) or fails open because the contacts are coated with carbon / the diaphragm is hardened (symptom: power is present at the pressurestat, but current does not flow).

Twenty-five years of service from a Sirai pressurestat is impressive. You can inspect the contacts to confirm, but it's a safe bet that replacement is long overdue.

Thanks for the prompt response....Yes, after 25 years it needs to be replaced. As you stated the OPV starts gushing water and steam. Other than that the machine, named Sonia, is in perfect working condition. This the first time I have a major issue with her. I just ordered a new pstat on ebay. Thanks for your assistance.

Sounds good. For sake of correct terminology, I believe you're confusing the over-pressure valve (OPV, or sometimes called an expansion valve) used to avoid excessive water pressure (typically around 9 to 12 bar) and the steam boiler safety valve meant to release steam in situations like yours (typically around 1.5 to 2.0 bar).

Got it....giving some feedback my new pstat finally arrived. Install it and is all back to normal operation....better than beore. I was in need o a new one. Thanks for all he help.