Found my problem. Bright green buildup everywhere. Now I'm waiting on some Dezcal to come in the mail. I've always used Nestle Pure Life, which the 2018 report shows to have a TDS of 36. I assume this build up is from the extended lay up time.

The brew valve gasket had a well worn indention and was flaking away when I tried to flip it over, so that probably contributed to my issues.

I'm not sure if I should start a new thread in the water section and link to this or just post here. But after soaking all these parts in super hot water, all that green scraped off easily. Some of it just fell off. I'm wondering about my water. I've always used Nestle Pure Life in the tank, which has an attached water filter. After digging further, I found this for Nestle Pure Life:

pH 6.5-7.5
TDS 55-60
Total Alkalinity 7.5
Sodium 4.8
Chloride 6.5
Total hardness 14 ppm

By contrast my tap water is softened at the city water plant by sodium ion exchange and those numbers won't work.

pH 8.3
TDS 378
Total Alk 208
Sodium 132
Choride 78
Bicarbonate 278
Total hardness 3 ppm

I wouldn't know where to begin to fix my tap water. Should I continue using Nestle Pure Life or switch to something else? Gerber baby water?

Blue/green deposits are still a mystery to me, I think they are very complex. I wish Dr. Pavlis were still with us.

Blue / green is always going to be some sort of copper corrosion, and since your Pure Life water has extremely low carbonates I think you can rule out copper carbonate. I think it may be copper chloride corrosion. It doesn't look too bad, and I have seen much worse. On one of my used machines I had serious green scale on the mushroom that I know wasn't carbonate because I scraped it off and put it in a white teacup of white vinegar (5% acetic acid) and it did not dissolve at all. In my case it was concentrated where the plating had flaked off of the mushroom.

I think your best solution would be to ditch the Pure Life for purified (RO or distilled) water that you spike with bicarbonate. 100mg of potassium bicarbonate per liter of pure water is a very popular recipe (the rpavlis recipe) on this site. That gives you 50 mg/L alkalinity (as CaCO3 equivalent) which makes it much less corrosive than Pure Life, has zero harmful chloride or sulfate, and has zero hardness so you never need to descale.

P.S.
Nestle also makes a Pure Life with added minerals, but I would not recommend that for an espresso machine. It still has too low alkalinity and too much chloride. Your tap water is less than ideal as a mineral source - high alkalinity, low hardness, but too much chloride and sodium.

Thanks so much for your response. I've read through tons of water threads and I was still apprehensive. Like yours, once removed, the green stuff was clearly forming only where the plating was gone. I have since scrubbed it clean and I'm waiting on a couple gaskets before I reassemble everything. I'll definitively be changing my water to the rpavlis recipe.

Do you think that it needs to be descaled considering this is corrosion?

pig140 wrote:Do you think that it needs to be descaled considering this is corrosion?

I would say not. It's not clear at this point what those deposits were, but likely were not carbonates and a descaling solution may not dissolve them and may cause further corrosion. Give it a good flushing with distilled or the rpavlis water. After sitting overnight draw some water through the group and compare it with the source water to make sure there is no blue/green tinge to the water.

(FYI, There was an interesting recent post related to this: Is water's blue tint really being caused by chloride? )

Will do. Thanks again!

So at this point I have completely cleaned the e61 grouphead, and last night I did a full overhaul with new gaskets, brew valve, infusion valve, and exhaust valve. Once back together, I switched it on and noticed the boiler was heating but the grouphead wasn't. I flushed water through the grouphead and eventually it got up to about 184, but that was it. Shut it off for the night. I turned it on this morning and after an hour the grouphead got up to 150. Flushing water through the grouphead shows that the water coming from the boiler got to about 175 and then started dropping temp.

Descale the boiler? Check something else?

Did you ever check your OPV? As was mentioned early on that could be the cause of a thermosyphon stall.

I did the test Jim suggested and no water escaped from the return hose. Is there another way to be sure? I have the machine in my shop and open, I'll check whatever you guys suggest.

BTW It's holding at 193 now - which is exactly where I was when I started working on it. When I run it, the thermometer goes up to 199, but that's it.

Does the water still take time to come to the grouphead or is it instantly?
Maybe bump the pressure stat setting a tad?
I have this issue off and on


Randy