Hi,
My pavoni professional will overheat from time to time. When I turn it on and let it heat up, between 10 and 20 minutes, sometimes it won't stop between the desired pressure 0.5 to a little over 1.0. It will sometimes shoot up between 1.5 and 2. It's also happened a couple of times where it went over 2. Steam starts coming out of the safety valve. Again, it happens here and there. I use it 2 to 3 times a day.

Anyone would know why?

Thank you.

My guess:

Almost certainly a descale will straighten that pro right out. Maybe a pstat clean if the descale doesn't. When I see my girls doing that I know it's time to descale.

Could be the heating element is shorting. If you have a multimeter you can check the heating element continuity.

Thank you all for the replys. I descale on a regular basis. We'll into all these options.

My Zacconi Riviera (Eagle) has a similar pstat arrangement to the one in your machine. Just descaling the conventional way isn't the answer. Sooner or later, the copper pipe from the bottom of the boiler to the pstat will fill with crud. Remove it, blow/ream it out, and be sure that there's no crud left in the bottom of the boiler covering the hole for that tube.

Nunas is right.
Most probably the tube to the P-statbis blocked.