La Marzocco linea mini at 13 bars

Hello! We have a La Marzocco Linea Mini at work and I noticed it runs at 13 bars when brewing (+/- 10 bars on idle).

I will try to adjust the water pump pressure myself, but honestly, 13 bars seems excessive to me. I noticed the expansion valve was blue and leaking, so I cleaned it and adjusted it and it seems to be better. Brewing pressure is still a problem though.

So I have a couple of questions I hope you can help me with :

  1. Is there a way to adjust the pressure without taking off the back panel?
  2. Is it possible the increase to 13 bars is linked to more serious problems such as calcium deposits?
  3. Do you have any ideas for a possible course of action?

Thank you in advance for your help!!!

Have an excellent day.