Hello,
I've been using my Rocket Appartamento daily almost for 2 years and I recently added a Flow Control unit by ECM.
Prior to installing the flow control unit itself, I installed the brew pressure gauge and tried to understand how the brew pressure was set on the machine.

Even though the boiler pressure gauge is at 1-1.1 Bar, the newly installed brew pressure gauge spikes up to 14 bar during any extraction, even during routine backflush cycles.

my understanding is that the "ideal" brew pressure should be around 10 bar...
I've been doing a lot of research on this but since I'm pretty new how internals work, I'm really confused identifying the underlying factor...
I assume it's related to the over pressure valve. I checked the internal diagrams of the appartamento but there is nothing related to OPV. Expansion valve maybe?
Could you kindly help me identify the issue?
Thanks
Can

Where is the brew pressure being measured? If the gauge is teed into the E61 grouphead, then it's accurately reporting the actual brew chamber pressure. If it's teed into the hydraulics system before the flow control valve, it will show the pump output. Either way, you should adjust the pressure down to maximum you will ever brew at like 12 bar. According to this parts diagram (wholelattelove.com), the expansion valve is #14:



See How can I adjust the brew pressure of a vibe pump espresso machine? if you need a refresher. Don't worry about OPV versus expansion valve -- it's essentially two names for the same part.

Thank you Dan
I finally set the OPV to 10bar.
Thanks again
Can

Hi Can,

I also recently got an appartamento and I noticed the brew pressure is a bit high, by having to grind extremely fine to slow down the flow. I plan to get a brew pressure gauge to measure this a bit more accurately. Was the adjustment easy to do or was it challenging? I have seen on a youtube video that you have to turn the valve perhaps two full rotations to get the pressure down to around 10.

Thanks,
George

Hello guys. I purchased a Rocket appartamento weeks ago. I too got really high pressure going up to 14 bars when pulling a triple shot. 22 gr in, 44 gr out in 30 secs.

I purchased the lelit Pressure Gauge for E61 group head. Not being sure if the problem was the gauge, i purchased another screw on gauge from another company and got the same reading.

Thanks to this post, i was able to locate the OPV and changed it to 9 bars with the blind basket.

The funny thing is that i was expecting to have to dial in my grinder... i wasn't expecting to pull a shot with the new 9 bars pressure and get my 44 gr extraction in 30 sec... ??? going from 14 bars to 9 bars, same grind setting then when i was at 14 bars got me the same lenght of shot ( 30 secs ) lol !

anyway, thanks for this post ! really helpfull !

Here is an important update on my mod.

This morning, i got a rattling noise coming from the machine while pulling my shots. My instinct was to remove the glasses and cups on top of the machine. I pulled another shot, rattling was still present. Try holding the water cover.. changed nothing.

I looked at the pressure, the E61 grouphead pressure gauge would go up to 9 bars just like i wanted.

So here is a break down of what is happening.

When i pull a shot, at first and untill the pressure reach the desired 9 bars, everything behave normally. But when it hit 9 bars, and the pressure start coming down a bit, the rattling is happening. The gauge needle seems to bouce up and down a bit... and the ratling noise is there untill i close the lever down to end the shot.

First thing i did was put the machine back to the factory 14 bars. ( i cheated a tad a only put it back to 12 instead of 14 )

I pulled some shots, no more rattling noise. The machine is behaving like before.

I would like to understand what was happening. Is it safe to use it to 9 bars with the rattling noise ?

NB: i'm sure what i did to adjust the pressure was not only done properly, but it was also the correct over pressure valve. You'll have to take my words for it. I also only adjusted the OPV.

Getting more comfortable with the machine, i decreased the pressure to 9 bars again. No more noise. I kept the machine naked to see what was causing the noise the first time i did the adjustment cause i was suspecting it was only parts toutching and causing a rattling. I've been brewing at 9 bars for the last month, and it's working flawlessly. I don't understand why the machine gets out of the factory at a so high pressure.