WiggoNut Senior Member Joined: 4 Jan 2012 Posts: 21 Location: AL Expertise: I live coffee
Espresso: Izzo Alex Duetto II Grinder: Mazzer Super Jolly, Hario... Vac Pot: Yama Siphon Drip: v60, Beehive, Aeropress,... Roaster: Popcorn Stove Top
Posted Thu Mar 22, 2012, 11:26am Subject: Alex Duetto II: Weird Pump Noise
Hi Guys,
I noticed that when I am pulling a double shot of espresso the machine makes a 1 second "screech" about 5 seconds into the brew. I was wondering if any of you had experienced this and if it's bad news. It is running off the internal tank.
I have had the machine for about 1 month and bought from Chris Coffee.
jwoodyu Senior Member Joined: 31 Dec 2010 Posts: 705 Location: Michigan Expertise: I love coffee
Espresso: Allex Duetto II Grinder: Mazzer Major Roaster: Poppery
Posted Thu Mar 22, 2012, 11:29am Subject: Re: Alex Duetto II: Weird Pump Noise
WiggoNut Said:
Hi Guys,
I noticed that when I am pulling a double shot of espresso the machine makes a 1 second "screech" about 5 seconds into the brew. I was wondering if any of you had experienced this and if it's bad news. It is running off the internal tank.
I have had the machine for about 1 month and bought from Chris Coffee.
Man i would use the sound recorder on my smart phone an call CC right away. Depending on how my cups are arranged on the top it will setup a vibration that make some really odd sounds but I don't think that is what your dealing with there.
You know those people that want to tell you how to raise your kids but have none of their own? That is how i feel when someone with a kitchen appliance tells me how the merits or dis-merits of my machine or how to use it.
Stuart Senior Member Joined: 9 Feb 2012 Posts: 113 Location: TX Expertise: I love coffee
Espresso: Breville Dual Boiler Grinder: Baratza Vario Roaster: Air Crazy popper
Posted Thu Mar 22, 2012, 11:41am Subject: Re: Alex Duetto II: Weird Pump Noise
I don't have a Duetto, and there's a big difference between the OPV in my machine and that in an Alex; but that sounds like it could be the OPV opening up as the pressure reaches its set point. I hear something similar when I am backflushing and running the pressure up quickly without a preinfusion step, and it comes about 3-5 seconds after the pump starts (with an empty blind basket) or 1-2 seconds in (with a blind basket that already has some water in it).
Does it happen with a blind basket? Does it happen with an `empty' shot or when running a flush?
WiggoNut Senior Member Joined: 4 Jan 2012 Posts: 21 Location: AL Expertise: I live coffee
Espresso: Izzo Alex Duetto II Grinder: Mazzer Super Jolly, Hario... Vac Pot: Yama Siphon Drip: v60, Beehive, Aeropress,... Roaster: Popcorn Stove Top
Posted Thu Mar 22, 2012, 11:59am Subject: Re: Alex Duetto II: Weird Pump Noise
Called CC, they said it could be the expansion valve. So i'm going to back it off a little bit and see what happens. But Right now I get 9 bars when i'm brewing, so we will see what happens. Any more additional comment are welcome!
senorswiss Senior Member Joined: 10 Feb 2008 Posts: 212 Location: Indiana Expertise: I live coffee
Espresso: DuettoII Grinder: Mazzer Major, Maestro Plus Vac Pot: Moka Pot Drip: French Press, Aero Press Roaster: Modified HG/BM
Posted Thu Mar 22, 2012, 4:43pm Subject: Re: Alex Duetto II: Weird Pump Noise
Depending on your definition of screeching:
Perhaps it could be air getting in the line. If there's a small leak somewhere (Any drips under the machine?), air might be able to gather into a pocket in the line, then get pulled into the pump the next time you use the machine (I don't remember what the connection between the water tank and pump is like). Certainly after I have mine (also Duetto II but plumbed) disconnected and I hook it back up, I can tell when air goes through the pump. Does it happen on every shot? even back-to-back shots? If it's an air pocket, I would expect it to happen only after the machine has been sitting a while.
As for not happening during backflushing: My guess would be that not enough water is pulled into the machine for the air pocket to reach the pump.
Just an idea... and I would trust the guys at CC more than me.
WiggoNut Senior Member Joined: 4 Jan 2012 Posts: 21 Location: AL Expertise: I live coffee
Espresso: Izzo Alex Duetto II Grinder: Mazzer Super Jolly, Hario... Vac Pot: Yama Siphon Drip: v60, Beehive, Aeropress,... Roaster: Popcorn Stove Top
Posted Thu Mar 22, 2012, 7:36pm Subject: Re: Alex Duetto II: Weird Pump Noise
Thanks for all the thoughts. The sound was like a sneaky water balloon, when you rub it between your hands (if that makes sense).
So i adjusted the pump pressure down to 8.25 bars, then put it back up to 9 bars. Now there is no weird squeaky noise when I brew. I'll keep an eye on it over the next few days but seems like the "problem" has gone away.
WiggoNut Senior Member Joined: 4 Jan 2012 Posts: 21 Location: AL Expertise: I live coffee
Espresso: Izzo Alex Duetto II Grinder: Mazzer Super Jolly, Hario... Vac Pot: Yama Siphon Drip: v60, Beehive, Aeropress,... Roaster: Popcorn Stove Top
Posted Thu Mar 29, 2012, 12:45pm Subject: More like a squeak...
Hey Guys,
So I this issue fixed for awhile but now it's back. I remembered telling you that it did not make this high pitched squeak sound when i back flushed...well now it does!
I realized i might be over loading the portafilter so i have been weighing my grounds in ever time before shots. This seemed to fix the squeak when I made espresso.
However, with out fail the machine will now squeak pretty bad when I back flush. I adjusted the brew bars to 8.5 but it still gives me this problem. I might try and get a video posted soon...Any thoughts?
Posted Fri May 18, 2012, 10:35am Subject: Re: More like a squeak...
Hello, I own a Rocket Cellini Evo and I have the same problem. The difference is that I started to see the issue right after I switch from tank to direct plumb-in connection. It may be good to remark, now that I read your thread, that when you do such change you have, in general, to lower the pump pressure to compensate the line pressure.
That been said, couple of months have passed since this; some money invested in a pressure regulator and many many hit and miss tests, but few days ago I happened to start thinking about my 'pre-infusion' routine.
Machine squeaked when I first cool flashed it before first use in the morning, and squeaked when brewing started too for some seconds. What was the common denominator ? Could it be the 'half-way' lever pre-infusion routine maybe ?
When brewing, well it made more sense, I did the usual, flush, grind, tamp and engage portafilter. Then, right after, 'half-way' lever pre-infusion for some long seconds and finally all the way up to start the pump and the brewing. But why the machine squeaked at the first flush too ? Was water draining back to the filter during the time off ? Should I have to invest more money in a non-return valve ?
Well the answer seemed to be the same as in the first case.. when I finished brewing and I was cleaning the group, instead of engaging the pump to flush some water and brush the screen, I was putting the lever half-way again to get some water there enough to clean and avoiding pump noise.
So my current conclusion is: half-way lever was at some point emptying the path or the pump or something causing some dry starting. I stopped that practice and so far I haven't heard the squeak for some days now.
The second conclusion would be that the pre-infusion does not work as I expected, at least with my rocket. I thought that having the machine plumbed-in I would get the line pressure on my PF but apparently not and it makes sense that when I used to do it to clean the screen I got some super-hot bubbling water out and then it stopped like if it has to develop some more heat pressure on the group and then I could see more water falling. Is such behaviour a malfunction ? The manual features the double pre-infusion methods one being the half-way lever and the other being the insternal E61 group pre-infusion chamber and so on..
I had the feeling that the first method should let the water run with the water line pressure and that is not happening.
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