Thanks everyone for the advice. I do think it is the anti-vacuum valve, though maybe I didn't describe the leak location very well. How cool to have such experts on the machine here.

I've opened it up and the tiny O-Ring on the anti-vacuum valve is clearly split. I'm glad to find out I can get a replacement at Home Depot. I'm trying to find the replacement valve online and while I've found a few places that list the part # P2561- they all say out of stock. I've only found 2 sources in Europe that claim to have it in stock. I did reach out to the store that sold me the ECM to see if they can't dig one up for me, but I may as well just try replacing the O-Ring and be done with it if that works.

Also good advice on figuring out the descaling. I'll do that. And on the loose water valve, it was just a couple turns of the nut.

Thanks again for the feedback.

elsol wrote: but I may as well just try replacing the O-Ring and be done with it if that works.

So long as you didn't let it leak for too long, the teflon will probably still be in good shape. You'll get away with replacing only the o-ring at least a couple of times before replacing the complete valve.

Thanks again everyone for the advice. I was going to replace the anti-vacuum valve but didn't find it available in the US. But I ordered a replacement O-Ring from McMaster Carr and that has done the trick nicely.

Accidently put a similar thread in the Machine forum, but I'll follow up here since I have a similar question on a 5 year old Synchronika (well, almost 5.)

About a week ago the machine suddenly developed a leak out of the lower discharge port just above the drip tray when the machine was cold and not in use. This is the port that the plastic lines from the vacuum valve and expansion valve goes to via a T junction. It caused a bit of a mess since I don't pay attention to the machine when it's not in use as the leak overflowed the drip tray. The machine is plumbed in but not plumbed out. The plumbing is a Clive kit with a Homeland softening filter and pressure reducer - the machine gets exactly 30 PSI in. The steam also suddenly became noticeably 'wet' on first use - much more than the quick condensed water purge of the wand I'm used to. I have to dump a good 3-4 seconds of steam, wait 30 seconds, and then it's the nice dry steam I've had for the past 4.5 years.

I thought it was the vacuum valve since the first videos from WLL all pointed to a leak there causing that drip, but if I would have thought about it more I'd have realized that can't be it - the leak doesn't occur when the machine is on and at temp. Also examining the plastic lines while the machine is cold and pressured shows the water slowly flowing from the expansion valve assembly. Replaced the O-ring and plunger anyway on the vacuum valve with a rebuild kit from Clive, and it didn't fix the problem. Further research shows a WLL video where that constant cold leak from the expansion valve may be due to a faulty mushroom seal - just got a new one in the mail yesterday. However, my question here and the reason for all of this text - is that likely the root cause? That seal failing seems to be blamed usually on high line pressure, and mine is 100% 2 bar spec.

The top issue for wet steam I've found is blaming the solenoid valve having a leak or debris and causing it overfill the steam boiler. Can that also cause a leak through the expansion valve and out the discharge port? Is there something else I'm missing? Still using the machine - cutting the water at the input via the valve in the filtration kit obviously stops the cold leak, and purging some steam isn't some huge burden, but I want to figure out the root cause before it gets worse.

elsol wrote:Thanks again everyone for the advice. I was going to replace the anti-vacuum valve but didn't find it available in the US. But I ordered a replacement O-Ring from McMaster Carr and that has done the trick nicely.

Do you remember which o-ring part number was it? They have hundreds of those...

Eric can confirm which one he ordered from McMaster-Carr, but this is the one I ordered for the vacuum breaker valve on my Synchronika:
https://www.mcmaster.com/9396K12/
I also tried the Clive rebuild kit which did not seal properly; after swapping out the o-ring with the High Temp silicone one from McMaster-Carr, it worked as it should...

Josh

Old thread, but I thought I'd post the o-ring details for the anti-vacuum valve... what I've been doing is replacing the o-ring every time I open the machine for descaling (approx every 6 months). Takes a few mins and saves the hassle of having to open the machine when one fails...

I bought a bag of a 100 of these for $2.35 on Amazon and they appear to be a direct replacement:

AZ-S70007
007 O-RING SILICONE
70 DUROMETER RED, FDA
CS: .070″ (1.78MM)
ID: .145″ (3.68MM)

The dimensions in the description don't match exactly, but I received the o-rings with the dimensions above and they fit perfectly:
https://www.amazon.com/007-Silicone-Rin ... =1-1-fkmr0

Good luck,

jbmia