lparsons21 wrote: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?

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.

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:

Rotary pump conversion - balanced bypass or standard bypass model?

It could very well be that Alex has a balanced bypass valve OR it has some other feature in its hydraulic system to accommodate 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.

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...

lparsons21 wrote: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?".

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.

lparsons21 wrote: 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?

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.

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).

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.