Give this a try. Unplug the machine. Take the cup warmer off so you can get to the pressurestat adjustment. Put your screwdriver in, put a mark on it so you can count revolutions. Turn the adjustment counter clockwise (increase pressure) until it stops. The adjustment rides on a center post. As you tighten the post will raise up through the adjustment screw. Eventually it will push the screwdriver out of the slot. Now turn the adjustment clockwise (decrease pressure) 13 revolutions.

I am sure there is some variance in the pstats, but on my machine, that puts me at 1.1 bar. A revolution too few or too many is livable. I did this twice and my machine returned to 1.1 bar each time. Hopefully that gets you in the ball park until you can get the gauge replaced.

Here is the brew pressure adjustment screw and spring removed.

Canuck wrote:
P.S. I'm a cyclist and have been meaning to swing by Dundas with a friend of a friend who lives in Ancaster (I heard there are nice, hilly roads out there). Is it fine if we stop by and sample a shot from the Vibiemme? Just kidding...your wife would 'hurt' you.

Thanks Jason, I plan on posting in the Eastern Canada section on CG to let people know about the option of having a machine from U.S. retailers shipped to the UPS store in Niagara Falls and then picking it up. I only was charged PST and GST and no duty. I'll post the details soon. If you are ever going to be in Dundas, especially on the weekends, definitely come by. Probably you'll want an iced latte or something given the heat at the moment!

stefano65 wrote:Make it easier for you
do not replace the OPV valve body just replace the spring and if necessary the plunger, do make sure that the spring inside the valve that you are getting is stiffer then the one you are removing you can see the parts here the spring is number 46.
Stefano

Thanks very much Stefano. I was wondering if a more simple replacement was possible. I thank you for your commitment to service regardless of whether or not you supplied the machine to me!

cannonfodder wrote:Give this a try. Unplug the machine. Take the cup warmer off so you can get to the pressurestat adjustment. Put your screwdriver in, put a mark on it so you can count revolutions. Turn the adjustment counter clockwise (increase pressure) until it stops. The adjustment rides on a center post. As you tighten the post will raise up through the adjustment screw. Eventually it will push the screwdriver out of the slot. Now turn the adjustment clockwise (decrease pressure) 13 revolutions.

I am sure there is some variance in the pstats, but on my machine, that puts me at 1.1 bar. A revolution too few or too many is livable. I did this twice and my machine returned to 1.1 bar each time. Hopefully that gets you in the ball park until you can get the gauge replaced.

Thanks Dave, I ended up going through the tedious process of installing my probe K thermocouple into a portafilter (a very rudimentary scace) and pulling flush after flush, adjusting the pressurestat, to dial in the temperature. I was way too high on the pressurestat as you can imagine. I couldn't believe how many revolutions were necessary to get it right. I was up around 210F AFTER a 12 second or so flush. Eventually I got it down to 200-201F and pulled a shot. I think some of my timings of the boiler cycling weren't given enough time to stabilize.

So how was my first shot? All I can say is WOW! The difference from my Silvia was pronounced. A whole different level of subtlety and mouthfeel. The good news was that my brew pressure gauge, despite the OPV setting, was reading about 9 bar or so.

On another note, I received a personal email from Jim at 1st Line regarding this situation. He was even aware of this post last night and had a tech working on testing a new OPV and pressure gauge this morning to send out to me. Thanks very much Jim!

Thanks to everyone, I'll follow up when I have the new parts installed.
Cheers,
Kaelin

So, just to follow up, I received and installed the parts from 1st Line yesterday. Replacing the boiler gauge was really simple. I'm set at .8 bar right now. Others have reported 1.1 as a good setting but I need to play around with it a bit in conjunction with Eric's grouphead thermometer. I'm just a bit confused because as Dave (Cannonfodder) has posted, his VBM idles around 201F with a 1.1 bar boiler reading. Mine seems to idle between 208 and 210 at .8 bar. My flush seems to top out at 212/213, I stop flushing at 206, and get anywhere from 201/202 during the shot. I'm planning to dial up the boiler to 1.1 bar just as an experiment but any ideas or input from other VBM owners or testers would be appreciated.

The new OPV worked like a dream. Really fast and simple as well, only a bunch of water to deal with. I angled the machine back by propping up the front legs and put a walled cookie tray underneath to catch the water. I installed both a new plunger and spring, it seems to hold it's setting well and adjustments made are reflected accordingly.

Cheers,
Kaelin