Nimitzg wrote:After connecting the machine to the waterline I have noticed the brew preasure was over 9 bars (10.5 with coffee,11 with blind filter).

1.Did anyone experienced such thing?
2.when closing the cover (there is a good youtube series created by Clive coffee) I noticed a 1mm gap (on one side only) between the cover and the front frame.
Any idea how to align that ?

Those numbers look good and safe. Despite where I have the bypass spring set at on my rotary pump, increasing line pressure also increases bypass pressure. What is your line pressure, BTW?

-Peter

Thanks Peter.
I have no measurement tools to indicate what is my line pressure.
What is the bypass preasure? Does it have any effect on the brew results?

The pump has an adjustment on it's body for the bypass pressure. The bypass pressure is simply the maximum pressure the pump will be allowed to deliver. It's there for the safety of the downstream components. Should not affect brew results. Was just saying that on most (but not all) rotary pump designs, if you raise your line (input) pressure, you might have to re adjust your bypass spring to a looser setting to remain at 11 bar max (if that is the maximum you desire).

-Peter

I wouldn't hesitate to reach out to La Marzocco support. Chris, contact here in the US, has been great to work with. Had an issue with the app not wanting to connect locally, meaning I couldn't do anything to adjust the settings that were now locked in. Put me in touch with their engineer in Italy. In the end, I wound up deleting the app from my phone and reinstalling, which seemed to fix the issue. He is also sending my upgraded parts to address a vacuum breaker issue I started to see. If you think you are seeing an issue, it couldn't hurt to reach out.

Nimitzg wrote:After connecting the machine to the waterline I have noticed the brew preasure was over 9 bars (10.5 with coffee,11 with blind filter).

Did anyone experienced such thing?

Not sure if it will help but check out this posting here in HB. The video posted by the OP appears to be showing pressures similar to what you are reporting.

Thanks Don...this just made me more confus...

pcrussell50 wrote:you might have to re adjust your bypass spring to a looser setting to remain at 11 bar max (if that is the maximum you desire).

-Peter

Why would I want 11 bars of preasure at the pump when 9 bars are needed for standard medium-dark roast extractions? (Unless the brew gauge not showing the actual brew at the puck)
I did lower the preasure as my guess was that the direct water connection has raised the water pressure in aprox. 1.5 bars

Nimitzg wrote:Why would I want 11 bars of preasure at the pump when 9 bars are needed for standard medium-dark roast extractions? s

You wouldn't. It's just a safety so that if you made a choker puck or use a blind disc for back flushing, you don't go over a certain max pressure... say... 11bar. These pumps are physically capable of way more than 11 bar so it's reasonable to set an upper limit just in case. If you want a 9 bar extraction, make a puck that supports 9 bar.

TL;DR the pump bypass valve is a safety tool, not an extraction aid... unless you specifically want to use it that way.

-Peter

Is LMLM worth the price compared to Bianca or R58

Depends on how important flow control is to you. If it were not, I would get the LMLM in a heartbeat. Also, if you are handy with tools and willing control your flow with a dial that you add, instead of the stock start-stop switch, you can mod the LMLM for flow control.

With absolutely no tech to back up my opinion, this the path I would take if I were in the market for new pump
machine.

-Peter