Izzo Alex HX - Pump Runs Constantly - Page 2

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#11: Post by toots »

I have swapped relays before with other types that didnt fit, glueing the relay upside down on the pcb and using wires so solder the relay pins. Pump uses NO normal open contact. If pressure buildup after 4 seconds = very normal. E61 grouphead has a pressure chamber to fill for cofee infusion, giving grinded coffee the time to swell.


#12: Post by JRising »

If you let it idle much longer, does the wait time take even longer?

If your brew-circuit water is escaping, then as the brew boiler (and the pipe through the steam boiler) reach boiling temp, the steam will expand and displace brew-circuit water to wherever it can escape. Eventually the brew boiler will be half empty and when you begin brewing it takes a few seconds to replenish the water before the boiler is full and starts displacing water out the head.

Potentially the brew circuit could leak externally and you would see the water inside the body of the machine somewhere.
It could leak over the boiler-fill solenoid valve and you may see this as the steam boiler pressure rising drastically on a really long brew.
It could leak over the brew valve, you might see it as steam or drops coming from the showerface, or drops dripping from the E61 drain while idle.
It could leak backward from brew circuit, over check valve toward pump... If the check valve gets hotter and hotter at idle, uncomfortable to touch hot, not just proximity to boiler hot, then boiler water is flowing through it in the wrong direction.
It could be leaking over the OPV functioning as an expansion valve... You can take the hose off of it and watch for water or steam AFTER the brew circuit is fully up to temp, it's supposed to relieve while the brew boiler is heating furiously.
I suppose it could be leaking from the heat exchanger or something else invisible, but again you might see the drastic rise in steam boiler pressure if so.

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#13: Post by cafeIKE »

Is that from an open group? It could be a thermosyphon block or leakage from the group.

You may want to keep a blind basket in the portafilter.
Water should then flow almost immediately.

After a shot, insert pf w blind basket, but don't fully lock, start pump & wiggle the handle the handle a couple of times and then full lock and stop the pump.

Wait an hour.

Remove pf, start pump and if flow starts immediately, problem solved

Enz0man (original poster)

#14: Post by Enz0man (original poster) »

I took a quick video of what happens. This is after about 15 minutes of idling after running water through the group for about 8 seconds.
The delay won't get any longer than this, even if I leave it on for an hour or more. I need to finish some work but I'll answer the questions above in a bit. Thanks!

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#15: Post by cafeIKE »

It's curious that the pressure gauge is zero, runs about 1 bar and then immediately hits 8 bar with no basket.
Can you look at the return line from the OPV and see if there is anything coming out of it before the pressure builds.

Hot is the group?
It looks like the entire water circuit is empty or stalled with some sort of blockage.

It's possible the boiler fill valve is leaking or there is a boiler leak.

I get that sort of operation if I drain some water from the boiler and try to engage the group while the boiler is filling, but get nowhere near 8 bar on an open group.

Enz0man (original poster)

#16: Post by Enz0man (original poster) »

Thanks cafeIKE for all the pointers. Finally got some time to look into this more.

Now I just want to make sure I'm understanding how the machine works, because I'm not quite sure I am looking at everything correctly.

This is a pic of the inside, and yes I know it looks like it's been through hell and back. Been debating taking the entire thing apart and restoring it. But anyways, from what I understand the part on the left that the tube is going into is the vacuum breaker.

This is down the right side of the boiler, and that would be the OPV down the side that the tube is going into?

The tube that comes off of that T in the rubber line comes out the front into the drip tray here.

No water goes through before it boils and builds pressure. And the group does get hot as if water is cycling through. No water leaks externally anywhere.

A few things to note though, after the boiler starts to build pressure, water will slowly but constantly trickle back into the water reservoir. Now that I say that, I remember the guy I got it from said that was an issue because he used the machine plumbed in and said it had an issue where the res would slowly fill up with water.

Also, there is no flow delay if I turn on the group before the boiler builds pressure. Anything below boiling, water flows right after I flip the lever.

I'm not sure if this is an issue but the boiler pressure seems to be kind of high. No matter what temp I set the PID to, the boiler pressure is 1.5 bar. Aren't HX machines usually somewhere between 1 and 1.3? 1.5 is right where the gauge goes from green to red. Safety valve is a 1.8 bar valve and has not released.

I'm still learning how everything works inside one of these machines, thank you for all the help I really appreciate it.

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#17: Post by cafeIKE »

I could not find a manual for the water circuit.

Does any water drip from the bypass valve tube into the drip tray?

Is the pump vibration or rotary?

Enz0man (original poster)

#18: Post by Enz0man (original poster) »

It has a rotary pump. There is no water dripping down into the trip tray. It only emits steam as the boiler reaches boiling point right before it starts pressurizing.

This morning I took the anti-backflow valve out to inspect it, and I found the O ring is completely gone and disintegrated. I assume that would be why water is allowed to trickle back into the reservoir.

http://coffeetime.wikidot.com/izzo-alex ... turn-valve

This is the link that WWWired PM'd me that I used, the pictures at the bottom show the valve taken out and the O ring that is supposed to be there. Not sure if I can source a new one, I'll try looking online or taking the part to a local place. The good thing is there's no scale buildup, but it's currently soaking in descaler just to be safe.

Enz0man (original poster)

#19: Post by Enz0man (original poster) »

Well I just put the whole thing back together and fired it up just to see if it still showed the same behavior (which it does), turns out my vacuum breaker had a leak, which is odd considering it's one of the parts I replaced when I first got the machine. But when it's up to temp, I can see some steam bubbling out of it. It was just never enough for me to notice it out of the tube going to the drip tray.

Oh well, add it to the increasingly expensive list I guess :|

Enz0man (original poster)

#20: Post by Enz0man (original poster) »

I've observed something after having the machine back together for a couple days. After cleaning that check valve and putting it all back together, the issue isn't as bad now especially after the first brew. When I first turn the machine on and flip the lever for the first time after it's fully heated up, it takes about 3 or 4 seconds for water to start flowing. But any subsequent brews after that, when I flip the lever it actually lets out a bunch of steam and does a "cooling flush" like you're supposed to do with an HX machine. The wait period for water to start flowing doesn't get any longer than ~1 second now even if I let it idle for an hour or more. So it's better now even without an O ring in the valve. The pressure still jumps to 8 bars on an open group though.

Here is a video of what it does now. This was after idling for about half an hour: