My Gaggia Carezza's steam water tube (the one that goes from the reservoir directly to the boiler) is flowing backwards. So when I turn on the steam setting, it just pumps boiling hot water out of the tube instead of sucking cold water in for steam. Needless to say, this makes it impossible to make steam.

I did take the machine apart (including the boiler) and put it back together in order to clean the boiler. (There had been HUGE scale build-up since I'd neglected to de-scale it for a year or more -- I know, bad plan.) I was pretty sure I'd put it back together properly (I kept close track of where parts went, and took photos as a guide, too), but now I'm not so sure.

Can someone please instruct me on how to fix this problem? Failing that, any insight into how that particular input hose is supposed to work (I don't see a pump in the boiler, and the main pump doesn't run when I'm just heating the steam up) so that I can troubleshoot it myself. A link to a repair guide would also be nice. (especially a layout of plugs and their purpose -- it'd be nice to disable the heaters so that I can troubleshoot without burning myself repeatedly) Thanks a lot!

FYI: My wife is desperate for coffee and the machine's been busted for over a month, so I cross-posted this same question to alt.coffee, wholelattelove.com, and coffee snobs

This is likely a problem with the self priming valve. Many have recommended a modification to disable it. If you go to the Gaggia Yahoo group there are instructions on how to eliminate the problem. Basically, you remove the tube and block off the valve. I will attempt to post a link below. You probably will need to join the group.

http://groups.yahoo.com/group/Gag...ods%20%26%20Hacks/

Looks like the problem is that I lost the rubber valve in the steam tube valve, so the valve isn't valving.

Closing it off seems rather drastic, and it eliminates the convenience of self-priming. Do any of you know where I could find that little ball as an individual part or even a new steam assembly (including said ball)? I've checked here (WholeLatteLove), Cereni Coffee and Cafe Parts. None of them have it listed.

Are there other assemblies I COULD purchase that would have that part?

It might take a phone call. You might also try partsguru.com, link to the Carezza parts diagram there.

I would suggest attempting the modification, as many seem to believe that this valve is entirely unnecessary.