Alex by Izzo - rotary pump you don't have to plumb in! - Page 4

[Psyd]

I just checked since switching over is so easy on the Alex.

I stand corrected. There is a change.

With pourover - brew pressure is 8.6 bar
With plumbin at 4bar - brew pressure is 9.1 bar

This doesn't seem to be a huge change, as indicated by cannonfodder, but since you're holding an Alex in your lap, it seems to be accurate. So, if I wanted to make sure that I stayed at 8.6 Bar, how difficult is it to adjust? Oh, and does the boiler autofill? Would the thing survive being left on all day, if plumbed? Does your manual refer to any of this?

[lparsons21]

This doesn't seem to be a huge change, as indicated by cannonfodder, but since you're holding an Alex in your lap, it seems to be accurate. So, if I wanted to make sure that I stayed at 8.6 Bar, how difficult is it to adjust? Oh, and does the boiler autofill? Would the thing survive being left on all day, if plumbed? Does your manual refer to any of this?

Well, not exactly in my lap!

Adjusting the pump pressure is easy. 4 screws to remove the top and then lift the 3-sides-in-one panel and you are inside. The pump is easily accessible and just as easy to adjust. Probably 5 minutes or so to do.

Yes the boiler autofills and it has an autocutoff if it runs out of water, with alarm. I don't keep mine on 24/7, but I have it on a timer to switch on at 7 AM and off at 9 PM. That allows it an hour to be toasty warm all over in the AM and I don't drink coffee of any sort after 9PM.

[erics]

What Dave (Cannonfodder) says is very correct because the rotary pump in the great majority of espresso machines so equipped has a standard bypass relief/regulating valve vice a balanced bypass valve.

This post sheds a little light on the subject:

http://www.home-barista.com/forums/post13825.html#13825

It could very well be that Alex has a balanced bypass valve OR it has some other feature in its hydraulic system to accomodate that change in inlet pressure. A balanced bypass valve (if so equipped) won't be perfect in its intended function but it sure would be interesting to see what a 1.0 bar, 2.0 bar, & 3.0 bar inlet pressure does to your brew pressure. My guess would be that the pressures would get closer and closer as you reduced inlet pressure.

Eric S.

[lparsons21]

I only described what I saw on the Alex and no other machine.

Whatever they did works fine, though you do get a reduced brew pressure when in pourover and probably with a reduced inlet pressure. However I don't have a regulator on mine and have no plans to get one as the performance is great. But this has made me want to adjust the pump pressure downward a bit...

[Psyd]

I only described what I saw on the Alex and no other machine.

Which is what I asked. I know about the dependency of the rotaries on incoming pressure as to tehir output pressure, as I went through a bit of an issue when the city's usally steady (but low, miserably droopy-shower low) water pressure suddenly went up to something that one could shower with, but boosted the brew pressure to over ten Bar. I adjusted for their adjustment, and got the BP down to eight and a half Bar again. Two weeks later, of course, the city went back to it's original level and so dropped my brew pressure.
This prompted the question of how well the Alex deals with that, and if, in fact, it does. It seems that it does, so that begs the question, "How?".

[lparsons21]

I don't know how the Alex is doing it and I'm really not that much of a tinkerer to want to dig around the innards.

But for info, Chris is sending a supplement to the manual with the Alex saying that if you change from pourover to plumb or vice-versa, you may need to adjust pump pressure. Complete with instructions on how to do it. I did that today, taking mine down to 8.6 bar. Trivial process, took about 5 minutes as I thought it would.

That did help in brewing cafe cremas, and the espresso shots are still just farging wonderful!

Whether you can taste the difference between 8.6 and 9.1 rests with your palate.

[Psyd]

But for info, Chris is sending a supplement to the manual with the Alex saying that if you change from pourover to plumb or vice-versa, you may need to adjust pump pressure. Complete with instructions on how to do it. I did that today, taking mine down to 8.6 bar. Trivial process, took about 5 minutes as I thought it would.

I know you said that you weren't a tinkerer, but how difficult do you suppose it would be to add a small hole, or an extension on the adjustment, or some other method of quickly adjusting it without removing the cover, if you were a tinkerer?

[lparsons21]

I know you said that you weren't a tinkerer, but how difficult do you suppose it would be to add a small hole, or an extension on the adjustment, or some other method of quickly adjusting it without removing the cover, if you were a tinkerer?

It sits at the back left side, with the adjusting screwhead facing the left side. That would be relatively easy to cut a hole to get access. BUT, the locking nut would need to be available that way also, and that's the rub, imo. And I don't think (but don't actually know) that you could loosen that nut and just let it remain loose and have the adjustment hold.

[cannonfodder]

That is a surprisingly low change, especially from 0 to 4 bar mains! There is definitely something extra ordinary going on in there.

Out of curiosity, what is the input pressure spec on the Alex? 4 bar is pretty high for input pressure. I ran my Faema two group at 3 bar but that was with a delay on make relay to allow for mains preinfusion before the pump engages. My new Elektra A3 spec 4 bar max but appears to work best at around 2 bar mains (preinfusion thing).

[lparsons21]

I don't know what the input pressure range is for the Alex. Nothing in the book about it and nothing on Chris' website about it.

Maybe Chris will see this and respond.

[Psyd]

Maybe Chris will see this and respond.

I have to say, this was the next machine to grace the butcher top of my dishwasher, but lacking answers to some of the more pertinent questions that have been raised here kinda knocked it off it's perch. I'm going to stay pro...

[lparsons21]

All I can tell you is that I have exactly zero problems with my Alex and wouldn't hesitate recommending it to anyone wanting a machine in this class. It is solidly built, easy to get into to make any wanted adjustments, and appears to be easy to service.

Coupled with the fact that it produces a superb cup whether it is an espresso shot or cafe crema and the ability to steam in fine fashion and you have an excellent all around machine.

I would say that its single downside is size.

[chris]

What is it you wish to know? I do not watch all the various web forums all the time. If you have any questions all one has to do is either call me or email me. There is no reason to put a hole in the side of the Alex to adjust the rotary pump pressure. First of all it would serve no purpose since you have to loosen the lock nut first before making an adjustment the same way you do on all rotary pumps. Second once you set it, it's set unless you have line pressure that varies greatly. In that case it would be recommended to install a regulator with gauge and set the pressure some where between 30 to 40 psi.

[Psyd]

What is it you wish to know? I do not watch all the various web forums all the time. If you have any questions all one has to do is either call me or email me. Second once you set it, it's set unless you have line pressure that varies greatly. In that case it would be recommended to install a regulator with gauge and set the pressure some where between 30 to 40 psi.

Hey Chris, thanks.
I've asked a few time (of the owners) about manufacturer's suggestions along the lines of 24/7 operation and all I got was a response that said, if I may paraphrase, "I wouldn't want something on at my house when I wasn't home". There was the question of NSF approval, and then, in regard to the pressure question, how much of a trick is it to unhook it from three or three and a half bar of line pressure and switch to the pourover tank? I would guess that it isn't the simple unplug and flip a switch that was discussed on another thread?

[chris]

I will be in my office all day tomorrow call me and I will be happy to answer your questions.

[Psyd]

As I understand it (Chris, jump in if I got anything wrong) these are the answers I was looking for:

The Alex Izzo is not approved for commercial use. This doesn't mean that it isn't qualified, it means that she hasn't been through the process. As far as I know, she probably won't. This is my guess. As the machine is really headed towards the higher end home use market, the added expense for a qualification that won't benefit the targeted market isn't warranted.

Changing from line pressure to pourover will change the group pressure somewhat, but not on a one-to-one basis. Estimations are a half-bar drop in pressure, with the caveat that it will depend on what that line pressure is to begin with. A half bar drop isn't that significant to me, and if it becomes so, it's easy to get to and adjust.

24/7 operation runs the risk of making a mess in the event of a Pressure stat failure (as they fail in the 'heat' or 'on' mode more often than not). Attempts at adjusting the deadband increases that risk of failure. I'd be willing to do an annual Pstat replacement to reduce that risk in exchange for having the thing available 24/7. Annual replacement will not guarantee that it wont fail, and neither will turning it off every day, as the Pstat is an electro-mechanical device and as such is subject to the entropic stresses that all moving parts are subject to, but its a conservative risk reduction. A bargain at twice the price in my estimation.

This is all my supposition based on the conversations that I had with Chris Nachtrieb at Chris' Coffee, and I may not have gotten everything spot-on, and there is a chance that I misunderstood completely. Do not call Chris and quote these words back to him, as they aren't his words. they are my best understanding of his words. He was very nice, very patient, and was willing to go to great detail to make sure that I was comfortable with the next machine that will grace the butcher top of my dishwasher, deposing my professional two-group.