Greetings,

After descaling our Izzo Alex Duetto III with citric acid a few anomalies occurred. After several flushings, the pressure built up in the steam boiler beyond 2-Bar and before I could release it by opening either the steam or hot water valve the over pressure safety valve in the steam boiler activated with a loud, startling bang that almost sounded like a gun shot going off in the kitchen.

The next anomaly occurred a few days later as the pressure of the hot water out of the hot water spigot diminished considerably, just as when there is scale build up restricting the flow. I thought it might need another round of citric acid. The next event occurred several days later as well, as a flood of water on the counter where the espresso machine is. Luckily we were home and right there to notice this as the machine is direct plumbed and might have returned home to a disaster had we not been there.

Time for an automatic cut-off in case of water spillage!

The question is can this safety OPV be disassembled and repaired or does it have to be replaced?

The attached pic shows the safety valve just to the left of the neoprene water hose, where the water gushed out of the holes just below the hex fitting.

BTW: I've descaled this machine before with citric acid & no ill effects. What might be up with it this time?

TNX

I had a somewhat similar experience to you a couple years ago. I fiddled around a bunch before I figured out that the steam boiler fill solenoid wasn't closing properly as a piece of scale dislodged and got stuck between the contacts. It was a bit of a pain to get to the solenoid but that solved the issue. I did replace the steam boiler OPV then just to be on the safe side.

P.S. It also happened right after a descale. And the fill solenoid was easy to take apart and put back together. I think Clive Coffee had a how to as well.

Leave the safety valve alone, it sounds like it's working perfectly.

Find out why the machine is overfilling or overpressuring and fix the problem. If it's not the boiler-fill solenoid sticking open as mentioned in the previous post, also check that the boiler fill probe is clean. Junk left stuck on the probe after a descaling could be giving it a path to ground. An underfilled boiler will overheat quickly with the PID supplying the power to heat a full boiler, more quickly than the PID can correct for. Heating an underfilled boiler is terrible for the element.

Thanks for your replies - you guys are a BIG help; I appreciate it!

I think you're on to something regarding the solenoid valve and I have looked through a previous thread Hasin posted.

Before attempting the repair I just would like some input regarding my observations and analysis. First I was wondering why there would be a flood of water through the safety valve with the machine 'OFF', Boiler cold and no heat as soon as the water inlet valve was opened, as the machine is direct plumbed? It occurred to me that the water line pressure of our house is about 4-Bar - well above the 1.9-Bar of the Safety Valve; perhaps that's why.

First course of action will be the disassembling of the solenoid valve. I was wondering how you removed yours Hasin? I was also wondering if it's possible to service this component 'in place' by mechanically disassembling it without mechanically disassembling its plumbing to the connecting tubes as it appears to me that the flow path and passages are all facing up.

If this might be possible, as I suspect that it might be, does any particular care have to be taken so that no spring-loaded parts fly off into the ether of the 'Nether' reaches of the machine?

BTW: My background is in electronics, amateur radio, geothermal design and hydronic heating & cooling so it's not beyond what I'm capable of understanding and doing - although I hate working on my own equipment!

Thanks for your time, thoughts, experience and expertise.

Steve

You're lucky your solenoid is installed the right way round - you may be able to disassemble it in place. I think you need to remove the spring clip and then try and get a wrench in to clean the valve. But unless its a big piece of scale that you can pick out with a tweezer you'd have to remove it to clean it anyways. It was a real pain in the butt trying to get that out and back in on mine, especially as it was installed the wrong way round too.

I took apart and cleaned the solenoid assembly with these results. Whereas before the rebuild the steam boiler would begin leaking immediately out of the safety valve when the line water valve was opened. After rebuild with power 'OFF' there was no leak. Turned power 'ON' no leak.

I allowed 1-hour warm-up - no leak; things 'seemed' normal. I opened the steam spigot and there was a gush of hot water as if the boiler had over filled. I opened up the hot water spigot, there was a severely restricted flow as if it was still all scaled up.

Things really started to go South when I released sufficient water from the steam boiler to activate the pump. Boiler pressure kept rising and leaking commenced. I would open either the hot water or steam spigot to reduce pressure that shot up again immediately into the Red so I shut 'OFF' the power to the steam boiler to save the heating element, not trigger the Safety Valve and shut off the direct water line to kill line pressure.

So something is still very wrong. Not likely the steam boiler safety valve because it held for at least 1-hour of boiler heating up and another hour of just water line pressure, no power. I suspect that the problem might still be the solenoid valve being defective and perhaps no reseating properly after activation. Solenoid valve I suspect is only activated with the pump, which does not leak. The other possibility might be a defective steam boiler fill level probe - or something else that I have yet to think of.

I have studied carefully an exploded diagram of the machine and was able to easily follow the flow of water throughout the machine A to Z.

What I might try on the next go around might be to run the machine off of the internal reservoir so as to possibly avoid a kitchen counter flood.

Attached pic is of the internals of the solenoid assembly before cleaning. I forgot to take pics of the plunger that mates to this that seemed to clean up pretty well. That plunger had a small internal spring loaded assembly and a small orifice on the opposite end at the external spring end and another at the top kept closed by the internal spring. The attached pic of the exploded solenoid is not an exact replica but pretty close.

But first there is still an underlying problem that I have been unable to resolve. This hoping someone here might have some idea...

Quite disheartening, thanks for taking the time to read and think about this too.

Steve

BaristaBoy E61 wrote: So something is still very wrong. Not likely the steam boiler safety valve because it held for at least 1-hour of boiler heating up and another hour of just water line pressure, no power. I suspect that the problem might still be the solenoid valve being defective and perhaps no reseating properly after activation. Solenoid valve I suspect is only activated with the pump, which does not leak. The other possibility might be a defective steam boiler fill level probe - or something else that I have yet to think of.

Leave it sitting electrically off, but turn its waterline back on and watch it and listen. Can you hear any water flow after the initial equalization of pressure as you open the valve? If that solenoid valve is leaking again, you should be able to hear it with the machine off. You might have to open it again and get more crud out.

If it doesn't over fill with the power off, water on for a half hour or so, let's consider the solenoid valve fixed. Now we move on to the boiler fill probe. A good cleaning of the probe, maybe with fine grit sandpaper or fine steel wool should get it all nice and shiny. Nice and shiny should get the boiler fill circuit to stop overfilling the boiler.
Good luck, let us know how it goes.

The results of the latest test are, with the power 'OFF' and line level water 'Opened' and reading about 4.5-Bar on the 'Pump' gauge that is normal for our house, there was no leakage out of the steam boiler safety valve as there always was before but this time there was a constant and steady sizeable flow of water out of the silicone tube originating near the expansion valve and ending up in the drip tray. At least there was no flood on the kitchen counter this time.

I haven't had enough time yet to determine what this might mean. Perhaps it is related to the last position of the solenoid valve when I last killed the power. Perhaps now the over flow is coming from the brew boiler and not the steam boiler but something is still wrong; it might or might not have to do with the steam boiler fill level sensor.

I think it's solenoid related. I don't see what else might cause a leak like this.

Thanks for hanging in there with me!

This update is a follow-up for those that have replied and as a possible future reference for those that may experience similar problems with this machine or others like it.

I rebuilt the solenoid valve by taking it aport and soaking the internal mechanical parts in vinegar and reassembling the solenoid. As suggested I also removed from the steam boiler, the water level probe that did have some deposits of some sort that I removed and cleaned with an SOS Pad.

After reinstalling the steam boiler fill probe, I partially filled the reservoir tank with water, switched the fill lever from 'Line' to 'Tank' and turned the water level Alarm Switch 'ON' to activate the magnetic Hall Effect cut-off circuit for low water level and filled the silicone hose to prime the pump that would not otherwise draw water.

I did this because of the last trial run that still leaked a lot of water, fortunately only into the plumbed in drip tray because I didn't want any repeats and noticed upon removing the water level probe from the steam boiler that it was completely filled. Running on 'Reservoir' I thought would remove the added complication of water at line level pressure while the machine tried to stabilize. It did stabilize, there were no abnormal water leaks what so ever. Pressures and temperatures were and remained normal both on the PID and on the pressure gauges.

I suspect that the last round of problems were caused by the malfunction of the steam boiler fill probe and perhaps the solenoid yet again (maybe the vacuum breaker). I flushed the steam wand that had quite a bit of water and then reverted to normal operation and opened the hot water spigot that ran very slowly.

I then switched from 'Reservoir' mode to 'Line Water' mode after I was sure there were no further symptoms of a problem. Everything held up with no problem other than that of the hot water spigot that I will address.

This whole episode has left me feeling quite insecure with regard to how quickly one might have a serious disaster with a plumbed in, unattended machine. I do feel that with 'normal' use this shouldn't be an issue, that these problems only likely arise after descaling. I do intend to install a sensor controlled automatic cut off valve to mitigate future water disasters. In the meantime I'm operating the machine in a 'hybrid' mode. The machine is in Reservoir mode when not being used and monitored. This allows me to continue to use our WeMo automatic timer so that when the machine turns ON and there is a call to 'FILL' that water is available with a limited supply and a magnetic cut-off to save the heating elements should all else fail and the reservoir be completely emptied. When actually using the machine, I manually switch back to 'Water Line' pressure so that I can continue to use line level preinfusion; when done I switch back to 'Reservoir' for peace of mind reasons.

This leaves me with the original problem of restricted flow from the Hot Water Spigot. The descaling of a few weeks ago cured this problem albeit temporarily, now it's back. I could disassemble and clean the Hot Water spigot assembly but the problem might also originate at the bottom of the steam boiler or even more likely at the right angled fitting coming out of the bottom of the boiler. This is the most likely cause. I will descale the machine again with citric acid and see what happens as this would be the simplest thing to start with doing. Should there be serious leaks again, I will know what to do. Thankfully the group has not been a problem.

Attached are pics that might be illustrative for those that might experience similar challenges.

Thanks for reading this if you've read this far!

This is just to conclude this thread and perhaps for those that might find there way here due to espresso machine problems after a complete descaling with citric acid that many vendors recommend that you don't undertake.

The second descaling completely cured the last remaining problem with this espresso machine that was in fact its first problem, that of restricted flow out of the Hot Water spigot wand. This was accomplished by another round of 2-oz of citric acid mixed into a full reservoir of water.

The procedure that I recommend is to carefully monitor the machine by remaining present and watching the steam boiler pressure gauge and PID display for any abnormalities. It would be prudent to have the end of the Steam Wand set up in a container so that should you notice exceedingly high pressure, that it can be immediately relieved by opening the steam valve before triggering the Steam Boiler OPV safety valve that would not be the end of the world but something to avoid. Should things not stabilize to your liking, you can then turn the power 'OFF' till you've determined your next coarse of action.

It's advisable to remain on 'Reservoir' until you're sure there will be further problems and you have confidence there will be no water leaks that could mean a serious kitchen disaster when direct plumbed and unattended.

One unexpected positive observation that I have always found after citric acid descaling has been that the group lever operates as if it has been disassembled and the cams properly lubricated - utterly silky smooth! One might expect just the opposite.

I hope this might help some out of a most aggravating situation.

I would like to once again thank the other posters for their help and encouragement.

YMMV