Sticky brew pressure gauge on Anita?

[quar]

Is anybody else seeing their brew pressure gauge stick on their Anita?
After pulling a shot, the needle remains at the last pressure it indicated. I can drop it back down by running the pump for a few seconds w/o a PF locked in, but it sometimes starts creeping back up.

Is that normal behavior for such a gauge?

Mike

[HB]

The brew pressure gauge should return to zero immediately following the "whoosh" of water into the driptray, then it will eventually creep back up as pressure builds in the heat exchanger. Try raising the lever halfway until water dribbles out, but before the pump engages. At that point the gauge should definitely return to zero. If it doesn't, time to call the service department.

PS: It's not an easy read, but the E61 patent description and diagram below explain what's going on at the lever's halfway position, specifically:

When lever (15) operating the cam (6) is lifted and thereby the lobe of cam lifts stem (16) of the dispensing valve (5), the dispensing valve (5) is in turn lifted off its seat against the force of the spring (18), permitting water under pressure to flow from the chamber (3) through the gicleur (2) and the valve chamber (20) and into the chamber (14) which communicates with the group via a conduit (4).

[quar]

Hmm....I've been wondering about that...I don't seem to be able to get water to dribble out of my Anita. Water doesn't flow until the pump engages.

Mike

[HB]

Well, it's not much water and it takes awhile for the pressure to build up. If you're able to make espresso and water evacuates as expected, you're golden. The rest is obsessing over minutia.

[quar]

The brew pressure gauge should return to zero immediately following the "whoosh" of water into the driptray, then it will eventually creep back up as pressure builds in the heat exchanger.

My pressure gauge can be unstuck by doing this, but it is not reliably returning to zero after ending a shot...Looks like I need to call Chris.

Well, it's not much water and it takes awhile for the pressure to build up.

I probably haven't been letting the handle sit at the halfway point long enough. I've only given it a couple of seconds.

Espresso has been great though!


Mike

[mrego]

Is anybody else seeing their brew pressure gauge stick on their Anita?
After pulling a shot, the needle remains at the last pressure it indicated. I can drop it back down by running the pump for a few seconds w/o a PF locked in, but it sometimes starts creeping back up.

Is that normal behavior for such a gauge?

Mike

I've had my Anita for about 2 weeks and noticed that I am having the same issue with the brew pressure remaining at the last pressure after pulling the shot.
I've just finished reading an article by Alex Lamber in the April/May issue of Barista Magazine (page 55), he states that this is normal.

I'm wondering about if this is just an issue with the Anita, or is it the norm for all other brands of espresso machines?


mrego

[quar]

I'm wondering about if this is just an issue with the Anita, or is it the norm for all other brands of espresso machines?

It's normal for all machines, not just the Anita.

Mike

[1st-line]

It's normal for all machines, not just the Anita.

Mike

Normal for direct plumbed machines as water line pressure will show, but it should go down on vibe pump machines unless the connection of the brew pressure gauge is placed behind a solenoid valve that maintains the pressure between the pump and the solenoid valve.

[HB]

I've just finished reading an article by Alex Lamber in the April/May issue of Barista Magazine (page 55), he states that this is normal.

I've not read the article, but I wonder if he was even referring to an E61 vibe pump HX machines like Anita. That's not the usual Barista Magazine fare. In any case...


Thermosyphon circuit and heat exchanger (solenoids / valves omitted)

When the lever is down, the system is closed. The idle pressure reading will therefore be partially from thermal pressure. Recall that the HX completely full of water and immersed in a bath of steam and super-heated water under pressure; after a few minutes, the gauge pressure will creep up as the heated water expands (an expansion valve will vent some water if the pressure rises too high).

I'm wondering about if this is just an issue with the Anita, or is it the norm for all other brands of espresso machines?

As Jim noted, it depends on where the tee for the pressure gauge is located (before or after the solenoid directing water to the group or boiler). For Anita, the tee is at the HX exit towards the group:


Brass expansion valve on lower left, HX exit toward group on upper right, brew gauge tee in center

See the threads E61 Group Espresso Machine: Detailed Interior Schematics and E61 patent explanation for more details / diagrams (thanks to Lino!).

[mrego]

The tee location for the pressure gauge is something that I had never considered. To me, it just seems a little odd having the Anita showing 7-9 bar or so, when
the machine is just sitting there and not brewing, but, what do I know. This just goes to show that the more you read this forum the more you learn.

Thanks for all that replied and educated me on my new purchase.


mrego

[Teme]

My Andreja does the same. I understand that the Isomac Tea also does this due to the location on the brew pressure gauge pick-up (don't know about other machines with a brew pressure gauge). I have always assumed it to be normal...

Br,
Teme

[kav]

I'd always heard that the pressure gauge reading wasn't meaningful unless the pump was running. My Anita's gauge has never sat at zero, but works perfectly when it needs to. No problem!