Wega Mini Nova brew pressure low.

[mgowens]

I purchased a Wega Mini Nova (black top) a few months ago off of ebay. I completely disassembled the machine to de-scale it. I replaced the group gaskets, mushroom, and the leaking anti-siphon. After re-assembling it I have found the brew pressure is down to about 6 bars. (it was around 9-10 prior to the 'operation'..)
This seems low to me.... Any ideas?

[HB]

If it is a rotary machine, it may be as simple as adjusting the pump's pressure relief valve. If it is a vibration pump machine, maybe the over-pressure valve (OPV) is releasing too early (the thread Need Help! Wega Mini Nova not working properly?!! discussed a similar possibility).

You will find a lot of threads discussing OPVs; the one excerpted below includes a helpful diagram by Jim Schulman and links to more background information:

Sometimes knowing where is should be located is more important that knowing what it looks like. Assuming your machine has a vibration pump, Jim Schulman's Adjusting vibe pump pressure on HX machines explains the mechanics, including the diagram below:

(reproduced with permission)

Tracing backwards from the overflow into the tank, you should find the over-pressure valve. However, if your Epoca has a rotary pump, the OPV setting is only for safety reasons should the pressure rise too high. Rotary pumps have there own relief valve (shown in this exploded view) that serves a similar purpose as an OPV for vibration pumps.