Quickmill Alexia with occasional delayed water from group

Need help with equipment usage or want to share your latest discovery?
Philg
Supporter ♡
Posts: 197
Joined: 17 years ago

#1: Post by Philg »

Sorry long post and it doesn't seem like a serious problem but I am curious if anyone has any ideas or suggestions.

When I engage the brew switch I hear a gurgle and the pump runs, a little water will come through the group but it can take 20 - 30 seconds before the gauge goes up to 6 (as usual) and the water runs normally.

I don't see any pattern. Not a thermosyphon stall - the group is hot.

Before this water stall happens the pressure gauge which usually sits below 2 will be all the way at the bottom.

When it's stalled I've tried opening the steam wand and turning on the pump with the toggle pump switch, but it's the same there - a long delay before water comes through the wand.

It can be weeks, maybe months between iterations of this.

Unrelated to this (as far as I know) normally the pump will labor for a couple seconds after water is flowing through the group, with the gauge rising slowly.

If I run water through the steam wand, for the next few shots (even over days) the pump labor is virtually gone and the gauge jumps to 6.

My guess is that I'm getting air our of the system somewhere (?) The two situations are different but I wonder if they're from a similar source and if there's any way to keep that air out of the system?

Thanks.

D'Laine
Posts: 68
Joined: 11 years ago

#2: Post by D'Laine »

This is familiar, I have the same problem too.
Just keep running the pump till water comes out the grouphead.
Maybe I left the lever down to drain overnight?

D.

Philg (original poster)
Supporter ♡
Posts: 197
Joined: 17 years ago

#3: Post by Philg (original poster) »

Thanks D.

Yes, though sometimes I will get two in a row, everything seems fine once the water is running - I'm just curious why it does it.

A while back I was getting thermosyphon stalls and before replacing a bunch of seals, I cleaned out the OPV and tightened it a tiny bit - after that, the machine seemed very "responsive" for lack of a better word, when pulling a shot the pump went instantly into quiet mode (no struggle) gauge shot right up, and eased slowly down after the shot.

Soon after I replaced the seals - no more thermosyphon stalls but back to the previous less responsive state (mitigated by running water through the wand) - I assume something I did (perhaps the OPV was a tiny bit looser) made the difference. The machine had always been that way, but I've seen videos of other Alexia where it appears "responsive." I don't know if this is better, worse or insignificant, but it seemed right to me.

The water stall seems more like blockage or something slightly misaligned, but I have no idea.

coffeesnob1
Posts: 63
Joined: 12 years ago

#4: Post by coffeesnob1 »

That is totally normal with all vibe-pump machines. The nature of the pump causes some cavitation as it vibrates. On my machine there is a pre-charge feature that builds water pressure prior to the valve opening which helps. Vibe pumps just by their nature produce some cavitation. Not sure if there is a way around it other than to bleed water out the wand until you get a steady stream.

Philg (original poster)
Supporter ♡
Posts: 197
Joined: 17 years ago

#5: Post by Philg (original poster) »

Thank you. I was getting ready to open up the machine and mess around - think I'll spend that weekend time working on learning the Pharos.

Thanks,
Phil

User avatar
erics
Supporter ★
Posts: 6302
Joined: 19 years ago

#6: Post by erics »

I would open up the machine "exterior" - Checking an E61 Espresso Machine for Scale using that link as a guide for scale on the mushroom assembly and a worn brew valve.

The fact that your pressure reads ~0 during the "event" tells me that the brew valve is leaking.

The pressure of 6.0 bar during brewing tells me the OPV needs a little adjusting, if not replacement of the sealing surface internals.

This should be mandatory :) reading for anyone owning an Alexia - Buyer's Guide to the Quick Mill Alexia - not necessarily in this instance but for the info it contains. I note that there does NOT appear to be a dearation/priming valve for the vibe pump in the pics and if your problem happens to sorta coincide with a cleaning of the reservoir, this would put a bit of air in the boiler.

I would flush water through the grouphead vice the hot water outlet until a steady flow emerges. Let the machine recover for a few minutes and then brew the shot as per your normal procedure.

Flow should come out of the grouphead essentially instantaneously as you lift the lever after the above routine.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

Philg (original poster)
Supporter ♡
Posts: 197
Joined: 17 years ago

#7: Post by Philg (original poster) »

Eric,

Thanks very much (as always) for your help.

I'm afraid in attempting to describe two circumstances:

1) the water stall

2) the regular variety of how quickly the gauge rises and the pump settles during non problematic brewing

in the same thread, I muddied the water considerably.

Am I right in assuming that the "water stall" is not normal?

And, that the "variety of gauge / pump response" with water coming out of the group right away is a symptom of normal cavitation, as coffeesnob1 pointed out?

The "water stall" symptoms are the gauge sitting low (zero) before engaging the pump, a spurt or gurgle sound when the pump starts, and no steady flow from the group for maybe 30 seconds.

To clarify, during a normal shot, the gauge pauses at 6 for about 5 seconds, before climbing to brew pressure (around 8.5). Water does flow just about immediately regardless of how quickly the gauge climbs, pump sounds.


I have recently replaced OPV seals and other soft parts - most often everything seems to be working fine, the water stalling happens rarely and I'd say at similar frequency before and after replacing those parts.

I was having thermosyphon stalls prior to replacing OPV parts and other parts, I haven't had one since.


Thanks,
Phil

User avatar
erics
Supporter ★
Posts: 6302
Joined: 19 years ago

#8: Post by erics »

The Alexia is unique amoung Quickmill machines in that the discharge check valve in the snout of the Ulka pump is the only item separating boiler water from the rest of the pump internals. If it had a deaeration/priming valve, that item also has a check valve.

Unfortunately, troubleshooting this requires that the case be removed and that you feel the brass section of the pump where it emerges from the plastic (discharge end). If this is hot/very warm to the touch, the check valve is allowing water to leak past the pump back to the reservoir. This would be time to replace the pump and the pump's mounts (as a convenient time issue).

During a normal screen flush, water should appear almost instantaneously. I do not agree with the "cavitation issue" under normal conditions.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

Philg (original poster)
Supporter ♡
Posts: 197
Joined: 17 years ago

#9: Post by Philg (original poster) »

Thanks Eric,

If there was a problem, would that brass section of the pump be hot all the time? The stalls when water doesn't flow are infrequent.

Thanks,
Phil