Brew pressure suddenly changed

fl13dl1c3

I’m puzzled with this observation of my MaraX. I’ve had this machine for 1.5 months now and out of the box the brew pressure always showed 9 bars while brewing as well as when backflushing with a blind basket.

Today when backflushing I noticed the brew pressure was showing 10.5 bars. I made another espresso to check the pressure while brewing and it showed as 10.5 bars as well. I’ve never opened up my machine to tinker with anything inside, so I’m just at a loss at why the sudden change? Any insights from anyone?

DavecUK

fl13dl1c3 Get a blind filter…pull 5 shots with 2 minute intervals, then wait 10 minutes and pull a few more…what does the pressure read each time.

dutchy101

I can’t comment on the Mara X, but this happens with my Minima when I use the blanking disk. I don’t think it’s anything to worry about but think it happens because the pressure builds higher when there is nowhere for the water to escape to unlike when you’re pulling a shot through a coffee puck and proper basket with holes in the bottom to release the water

EDIT: Sorry hadn’t read the post properly and saw that the pressure was pulling at 10.5 with coffee too

fl13dl1c3

DavecUK I did what you suggested and every blind shot was 10.5 bars

DavecUK

fl13dl1c3 I did what you suggested and every blind shot was 10.5 bars

Then I think you are safe to adjust the expansion valve a little. Open top, and you should see the expansion valve, you will need a spanner to adjust it.

fl13dl1c3

DavecUK Right, I remember seeing videos showing how to lower the pressure with the OPV valve.

I’m just scratching my head as to how and why the pressure changed from 9 to 10.5 bars suddenly without any interference on my end.

DavecUK

fl13dl1c3 I’m just scratching my head as to how and why the pressure changed from 9 to 10.5 bars suddenly without any interference on my end.

Dunno….but it seems to be consistent.

Giphy - Black And White Vintage GIF