Before you go replacing HXs, you want to make yourself certain that's what the problem is. I think the manual fill line(the one shown with the valve labelled in your pic) and the autofill enter the boiler in different locations. You want to physically disconnect these and still see the boiler level increase. The other way is to completely disconnect the heat exchanger, plug off one end and connect a water hose to the other.

Either way make sure you followed all the lines to ensure water can be sneaking in another way via a leaking valve before concluding the HX is cracked.

A general clue as to whether or not a machine has gotten frozen is to take a look at the gauges with the machine setting on the garage or shop floor. Needles that don't rest at zero normally means that the machine got exposed to freezing temperature with out the water being drained. Water becomes ice and destroys the tubing in the gage and can split boilers and heat exchangers. HX machines can be hard to get the water out of the exchanger. Just draining the steam boiler won't get it done...If your photo is of the machine unplugged, electrically and hydraulically, then good chance it got froze.
jpboyt

That's a helpful clue too, thanks. Yup, that's it's state unplugged.

And yes, I'll continue by taking out the heat exchanger and taking a look before I order any parts. All very interesting, this is. I may take this slow for a moment but I'm really appreciative!

Hate to ask stupid questions, but, uh, where is the HX? Not behind the group, I guess...

Glad everything I'm taking a part seems rather clean and in good order. A bit of scale here and there but ok.

Thanks!

MNate wrote:Hate to ask stupid questions, but, uh, where is the HX? Not behind the group, I guess...

Yep, thats it heat exchanger design varies, in this case it extends from that flanged group connection down into the machine. Its blind, so no exit at the other side, the brew water goes in thru that small diameter teflon tube hanging out the back of the group and goes to the group thru the larger blackened copper tube.

I can see what looks like the lip of the exchanger as the darker ring in the centre of the boiler flange, can you pry it out or even have a look see in there with a mirror/light? I haven't had one of these out but it seems that the exchanger is held in place between the 2 flange faces.

Curious to know what you find.

I was able to pull it out a bit, but then it gets stuck and I can't seem to get it more without some potential damage. Perhaps the rupture has deformed it? If it's broken it may not matter if I damage it.

So to see if it's cracked, shall I just pour some water in it? Water shouldn't escape if it's not cracked, correct?

And so I'm looking at this... Part #16, it looks to me... A "bent extractable exchanger"...

http://www.cafeparts.com/productDetail5 ... 7&ItemID=0

I would take the boiler cap off so you can see inside and finagle it out. Not a bad idea to test it for leakage before you pull it.

Boiler plate is now off and I've confirmed that the HX is, in fact, leaking. Still can't get it out. Tomorrow I think I'll hack saw/Dremel off the part I can get out and then I should be able to take the rest out easily enough from the inside.

Some build up on the inside but again, not bad. Now that I have the plate off I can clean it out better too.

Thanks again, all!

Stumped again. suggestions?

Replaced the HX. Indeed it was cracked and bulging so I had to cut it out.



Now I'm back assembled with the new HX and a cleaner machine (not much scale but I cleaned out much of what was there). The original problem is fixed but now...

After turning it on and the machine warming up for a while the pump kicks on and overfills and doesn't shut off (I shut the machine off, drain out the excess from the boiler - glad it's just a flip of a valve- and start over, at which point the pump is off again). Ideas?

Here's more info:
-if I have the boiler less than full and turn the main switch to 1, the pump starts, fills the boiler to the correct max level and turns off nicely.
-manual fill valve is off, drain valve is off, valve coming off the pump is on (though same issue if this is turned off, the pump then runs but doesn't fill the boiler)
-the anti-depression valve does open properly as the machine heats then closes again when I turn the machine off - not sure when it is supposed to turn off)
-the gauges are still wacky... The boiler pressure gauge stays at 0 but presumably because the boiler hasn't heated enough to build pressure (this gauge did work before). The dispensing pressure gauge is way out at crazy and hasn't moved - when the HX was cracked this one was moving crazy because of that.
-the dispensing button, up or down hasn't mattered. The machine doesn't warm up enough to have that or the volumetric buttons light up. (Draining the water after hearing shows the water is at about 150degrees)

So that's where I am... Something easy? Something difficult? Thanks for any help. I don't know how the machine is supposed to work so I may be disadvantaged to recognize what isn't as it's supposed to be.