I'm having a small problem with an excessive amount of water flowing out of the over pressure valve in my Vibiemme DD (version 2). When the espresso lever is lifted I am getting water flowing through the basket as expected and out of the over pressure valve in the drip tray. My guess is that the pressure valve is bad. Is this correct or is there a different issue?

Check with a bling basket simulating a back flush and keeping an eye on the gauge see where the OPV starts to open
adjust if necessary screwing in
or if no result and assuming that the scale is under control you might need to replace the closing gasket and spring
we have them as a kit on our web page but before buying part try the adjustment

of course this is also assuming that your showerscreen and all passages form brew boiler to grouphead are nice and clean,, if not water will find the path of less resistance and work her way out from the OPV

I adjusted the spring and that did help some. I wasn't able to completely fix it so I'll order the repair kit and probably a new OPV from you as well. One of these should fix it. Thank you for your help.