Dream Steam Boiler overfill - FIXED!

[goodboyr]

Just had a classic steam boiler overfill problem on my Dream.....but with a twist.

Symptoms: Water coming out of vacuum breaker at top of boiler, pressure going way over setpoint, mix of steam and water slugs from steam nozzle. I could draw off lots of water through the water tap before the refill pump came on.

Investigation: I checked the level probe (both position and cleanliness) and all was ok. And since the overfill was occurring without the pump coming on, I assumed the level control system was not the issue anyhow, but it was good to check to make sure.
Looking at the flow diagram, on the Dream, the boiler fill solenoid keeps the boiler isolated from the pump output and waterline pressure until a fill is needed. But if the solenoid is passing slightly, it would allow line pressure ( I have mine regulated at about 2.5 bar) to reach the boiler and slowly fill it.

I removed the solenoid valve and found the culprit: A tiny metal shaving sliver. I had read about this issue on other machines. I cleaned up the green rubber seat, and reinstalled. All is good. See before and after pictures below.

[chas]

Good catch. On the bright side this issue (in various locations) used to be reported all the time. Yours is now the first metal shaving report in a long time so at least LaSpaz seems to be doing better though not yet six sigma!

[goodboyr]

Thanks. I did note that the gicleur is different on the Dream. There is no adjustment or nut. Instead, the rubber seat mates against a raised spot with a tiny hole in the valve body. The water inlet enters the valve body through a larger hole at the periphery, and when the solenoid operates the plunger lifts off the seat via water pressure and enters the outlet line through this tiny hole. So the gicleur pressure reduction function is met by lifting the plunger against spring pressure and forcing the water through the tiny hole. If you look closely you can see the indent the raised hole makes in the rubber seat.

[Cu$hman]

plus 1 for my S1! Rusty metal debris on rubber seat causing boiler overfill. Thanks for the post!

[segur]

I just want to report that this problem still occures. I've bough a Dream-T machine less then a month ago and last week it started acting weird. The symptoms were a bit different at first—when the steam boiler was getting up to temperature, the coffee boiler suddenly started to overheat; afterwards, with the steam boiler turned off, when I tried to pull a shot, the pressure in the steam boiler started to rise quickly; only after that, when the machine was started from cold state, I've observed the steam boiler overfill.

Anyway, from the behavior, it was clear that the valve to the steam boiler is not closing properly and after disassembling it, I've found basically exactly same metal piece as the one on the photo above. The machine works well again after its removal.

[dhbdhb]

Hi
First post in this forum, thanks for having me :-) Have the same problem with my Dream-T. Have removed top, sides and back. Im not so technical (yet ) removed the steam break valve hoping for it to be the solenoid valve mentioned and depicted in Goodboyr's post. Could anyone point out the solenoid valve hard to see on the pict since it only shows the hidden part of the bolt :-)

[chas]

The Vacuum Breaker Valve is the one you have labelled as "valve opens while heating up". Actually it opens while cooling down and closes again while heating when it is working correctly. True to it's name, it opens while cooling to prevent a partial vacuum from forming in the boiler. When the boiler begins to create steam, the steam pressure forces the valve shut. So it is normal for about 15-30 seconds before closing that steam and some hot water spits out.

If instead, water pours out of that valve while it is open, then your boiler is overfilling and either the solenoid is not closing all the way or else the water level probe is not working correctly.

The solenoid in question is that black rectangular item in the upper right corner of your bottom photo.

[dhbdhb]

Thanks a lot Chas

Was actually about to write that I worked out where the infamous solenoid valve was. Unfortunately it was clean. Also took out the fill prope. few mineral deposits on it but not more than what could be cleaned off with a dry cloth. Anyways I get the intentional function of the breaker valve. Problem is that in 1 in approx 10 'heat-ups' the steam doesnt close the valve as supposed, with heaps of splashes of water escaping from the black plastic container around it ( it only takes a few ml). Also, the gauge for the steam boiler goes crazy into the red, steams comes out from around the steam-knob-handle and you hear the punp working continously. Havent had the guts to see how it ends, I always turn of the machine afraid it will explode or something. Any suggestions?

[dhbdhb]

So its in the warm up phase the problem happens and its a combo of steam and water that escapes (or maybe only steam that condenses to water fast). But its maybe caused, like you suggest, by to little empty space in the boiler (because of too much water) to create the pressure to lift the valve so it closes... ? what does one do about that, maybe start from the beginning, i.e. empty the boiler and fill it as descriped in the manual ?