Stinky steam

[cnadon]

I've got a Gaggia TE, heat exchange, machine that's plumbed in. The steam coming out of the boiler recently started to smell strange: a bit musty and maybe somewhat sour. (Same for the water coming out of the hotwater spout.) I drained the boiler, flushed it out a couple times, which cleared it for a bit. But it comes back pretty quickly. I think it might have started not long after doing a backflush. I'm wondering if there is some coffee from the grouphead that is leaking back into the boiler, perhaps through a hole in the heat exchanger? Any ideas?

Thanks.

[hperry]

Sometimes comes from milk getting sucked back into the steam wand. I always try to make sure that I expel some steam after steaming milk so this doesn't happen.

[cnadon (original poster)]

Thanks Hal. I'm pretty careful with clearing the wand. Would this account for the bad water back in the boiler that was coming out of the hot water spout?

[HB]

Absolutely. The same procedure for descaling will freshen the steam boiler.

[cannonfodder]

I had a boiler on a Faema get contaminated with milk and go skunky. Descale acid did not do much. I had to use backflush detergent (JoGlo) to get the rancid film out of the boiler. Same thing with coffee oils. I figured I would just drop the groups into the descale solution with the boiler. That would clean them up. Did not do a thing. The acid had no effect on the greasy, oily buildup but a bit of detergent cleaned it right up.

[cnadon (original poster)]

As Dave accurately reports, descaling helped, but did not clear up the whole problem. I ran some dishwasher detergent through the boiler and wand then rinsed several times. So far so good. Thanks.

[andtheodor]

Here's what can happen inside your boiler:



If your steam continues to smell, you might have to pull out the boiler and clean it.