This forum is now read-only

To login to the new support channel and community forums, go to the Support Portal

LR PreInfusion Module Check Expvalve warning

Hello! Just wanted to see if anyone has run into this before. I recently opened up my LR to adjust my PI for a lighter roast I'm using. I noticed that my PI module is displaying "Check Expvalve" or something along those lines. I'm going to order some things from the store and want to see if I should add any parts to address this if it's an issue. I don't recall seeing this message when I last changed my PI settings. Any input would be appreciated so I can combine things into one order to save on shipping.


  • The "Check Expvalve" is a routine remark indicating that at that higher pressure (12 bar or more) the expansion valve is dripping water back into the water reservoir which is normal. If this happens at a low pressure, say 8-9bar, then the expansion valve would need to be adjusted.

    Reiss migh add / correct.
  • hi andrew

    when we added the digital pre-infusion module to the LR we kept using the same manifold with the expansion valve in the top that has been used for years in many thousands of Fracino machines without issue

    however with the addition of the digital module it brings the ability to display an over pressure message, and so it was felt we should add one

    unfortunately this was programmed to display at 12.7 bar, which i think is too low, my preference is for it to show at 12 bar plus 10%, which would be 13.2 bar

    so your choices are to ignore it, or if you prefer you can adjust the expansion valve fractionally so it opens at closer to 12 bar, but you are likely to need less than an eighth of a turn counter-clockwise to achieve this

    there is a post on this in the permanent file

    i am also available on video call if you want me on hand to step you through it

    kind regards

  • edited October 2020
    Thanks Reiss and Frans! I'll check to see what pressure is indicated when the message comes up next time I open up the side panel to adjust PI (or installed the wireless module)...
  • My expansion valve warning kicks in at 12.3 bar. I presume that is fine and no need to adjust it down?
  • hi rob
    the message will show at 12.7bar; 12.3 might be the last number you see before the message appears if the pressure is rising quickly
    its nothing to worry about; a future release will show the warning at 13.2 bar
    kind regards
  • Hi Reiss,

    As per message on another thread, I'm going on what the app is showing me - it never reads higher than 12.3, at which point the display on the actual PI unit displays the warning.

  • yes, and what was the number that was displayed before 12.3? 11.9 perhaps? the pressure numbers increase very quickly if you take the time to observe them; this is the process of the newly introduced cold water being heated and trying to expand but with no where to go until the expansion valve opens. there is too much of a lag on the app to really see what is going on; watch the numbers rise directly on the console if you want to get a feel for it. reiss.
Sign In or Register to comment.