I purchased this M30 Classic in none working order after the heating element wires caught fire, and you can find my rebuild page here.

I tore the machine completely down and powder coated the exterior. I soaked the metal pieces in citric acid thinking this would remove all the build up. I took the pressurestat apart and rebuilt that and a replaced a couple other parts in the plumbing.

Regrettably I was unable to remove all the build up in the boiler and I reassembled the machine even though the boiler had a hard coating on the inside of the boiler. After I got the machine back up and running I had lots of scale working its way through the machine and really bad tasting steam. I wrote about this on the rebuild page and was told I should descale the system again with Dezcal.

I descaled the system 4 times with dezcal and the machine got much better and much better espresso. I have also had problems with the water exiting the water tap constantly boiling and splattering everywhere. Every time I descaled I used the machine for a couple weeks and then did it again.

Generally I drink straight shots and iced espresso drinks, but as the weather had changed colder here in Oregon, I tried to make a hot drink for my wife and realized the steam still tasted really really bad. So I purchased and installed new internals for the steam valves (the steam wands were already new) and this made no difference. Next I opened up the side cover on the boiler and spend an hour wire brushing and using iron wool to remove as much junk as I could from the inside of the boiler. I got the inside of the boiler fairly tidy, the steam still tastes really bad.

I am unsure if the water spout in unrelated to the bad steam, but sometimes after I descale or open something up it works normal (and flows smoothly like my other M30) and other times its splatters everywhere.

So, how can I fix this bad steam taste? The only thing I haven't tried is removing the copper lines that go to the steam wands and clean them with some pipe cleaners or something.

Please help me. I'm overwhelmed with frustration.

-
Craig

I took out the copper lines that connect the boiler to the steam valves and they did have some build up in them. I soaked them in some fluid to remove the build up, shot 1/2" pieces of pipe cleaners through them with an air compressor, soaked them in heavy concentrated citric acid, and used anything I could find to scrape the inside of the pipes out.

I reassembled the lines and tried the machine out this morning. It did make an improvement, but it still is not good. I'm not sure if the lines are whole problem or if the boiler is the of foul taste. Any ideas what I should do next?

Thank you,
Craig

Judging by the lack of response, there doesn't seem to be any ideas on how to clean out my espresso machine boiler and lines while in tact.

I spoke an espresso machine repair company and they claim that bad taste from steam means that milk got into the boiler. I tried one last descale of citric acid yesterday and the steam still smells.

So, I've decided to put my other M30 back into operation and remove the bad tasting boiler. And now I need to figure out the best way to REALLY clean the inside of the boiler.

What is the best way to remove any and all contaminants in my boiler. Steel wool takes some blackness off, but I cannot access every corner and want to remove even more what steel wool will.

Should I take it to a bead/media/sand blaster?

-
Craig

Your comment about lack of response to your thread is probably is not going to promote assistance. Moving on.
In your initial post you state you were unable to clean all parts of the boiler. In turn you still have contaminates and scale which is going to influence the taste of your water and steam.
It is true you can draw milk into the steam wand and foul your boiler. It happens more than people think. With that- if your boiler, steam path- pipes, fittings and valves are not spotless- you are going to have an induced funky smell and taste. And it is enhanced with temp.
I recently restored an M26 that had similar issues as yours. If the shop saw the pictures of what was in that boiler they would have lost their lunch. It took many days of repeated soakings in strong citric acid/ boiling water combination to all apropriate parts. You have arrived if the parts are bright brass or copper colored- nothing should be black. If you are committed to your machine - round two breakdown and cleaning. It will remove it- just takes time and perseverance. Just as a rule out- have you taken a water sample from the water inlet side, boiled, then tasted it and compared ?

Craig,
I would guess that by not removing ALL the scale/build up inside the boiler (as mentioned in your first post) you have allowed contaminants to remain, affecting the taste of the steam. I'm not sure if your 'one last descale of citric acid yesterday' removed ALL of the scale you mention in your first post.

Citric acid usually works quite well. You didn't mention what strength of solution you used, and if you used hot water or just room temp. solution. How long have you let it sit in the boiler? Hot water in solution seems to make the cleaning action more aggressive and speedy. A few hours of soaking with lukewarm water will likely not descale it to the level you need.

I recommend you again remove the boiler, plug all holes except your fill port and fill it with citric acid solution made with boiling water, and fill it as full as you possibly can. Wrap the boiler in a towel/blanket and let it sit for a day or two. You will likely have to rotate the boiler in order to ensure ALL areas (top area) are descaled.
Open the boiler up to scrape out the scale and descale again until you see pink copper (if your boiler is copper) throughout the inside of your boiler.

I would hesitate to media blast it until you've exhausted the citric acid avenue. That is just my opinion though; others may chime in with recommendations to blast it.

kize - I believe my comment about not receiving responses was misunderstood. I was not trying to be rude and complain that I was not getting a response, I was using the lack of response as evidence that there may not be a way to clean out the boiler while in the machine.

If patience and repeated soaking in citric acid will eventually remove all the contaminants, then I will certainly do so until it is clean.

Maybe I just haven't soaked it enough. My thinking was that the build up was so thick that the citric acid wouldnt break it down. But I hope you are right.

Here is a quick recap of my soaking of boiler. Please let me know if I should keep soaking or if I need to find another drastic method.

1. All boiler and parts removed. Soaking boiler and copper parts in strong citric acid solution with boiling water for 3 days.
2. Scrubbed inside of boiler with wire brush, steel wool etc. Repeated boiling water and acid. for 7 plus days.
3. Scrubbed used vinger.
4. Assembled machine. Later over filled machine with citric acid and hot water. Used heating element to keep water hot but not under pressure for 8 hours. Rinsed thoroughly.
5. Repeat citric.
6,7,8,and 9, Used Dezcal descale solution and used like citric acid above. Soaked once 15 hours not at temp.
10. Between Dezcal baths, Removed end cap on boiler and scrubbed with screw driver, steel wool, wire brush and vinegar.
11. Removed copper lines from boiler to steam wands, soaking in citirc acid, scrubbed, shot pipe cleaners through with compressed air,
12. Removed steam valves, soaked and scrubbed, replaced internals.
12. Citric acid bath like above for 12 hours.

In a week or two I will remove the boiler and go at it again. Thank you for the input.

-
Craig

I forgot to ask- is the critric acid you are using 100% and food grade ?

100 percent citric acid? I believe so. I purchase it at the home brew store, as it is purposed for wine making. I threw away my last package as I used it up the other day. Wouldn't the home wine citric acid be 100 percent? Now you have me wondering.

-
Craig

I'm not sure on that. I had to special order what I used. Have a bunch left over also. I don't live far from you- I could send you some of what I have left for the cost of postage. Pm me if you're interested

While citric acid is good for removing scale, if you have milk contamination in the boiler or steam wand piping the acid will not remove the oils. You need a detergent for that, I use JoGlo and it works like a charm. If the scale in the boiler has some contamination inter mixed in it, it will just keep leaching out into your boiler and give you stinky steam. Hot citric acid works much better than cold. When I did my restore work on the old 2 group I would bring the water to a rolling boil, then dump in the acid appropriate for the amount of water and soak everything. It works much more aggressively when hot.