civ wrote:Once the vacuum valve closes (under boiler pressure) both the boiler and the glass tube will be under the same pressure, so nothing is pushing anything.

civ wrote:If anything is clogged it is the tube at the bottom and not the tube at the top.

Not sure I am following your logic here.

If the top tube was clogged there would be no pressure to equal out the pressure coming from the bottom. As a result, wouldn't the water in the sight glass go up ?

I descale this machine often.. Maybe 4 times a year. I fill up the boiler with citric acid and let it sit for a few hours and then flush. I know the boiler needs descaling when it starts to knock when the element comes on.

But when I descale, I don't overfill the boiler (which might be a mistake). As a result, steam eventually causes scale to fill the top of the boiler and thus the top tube.

Thanks for the suggestion. I am going to start by taking apart the top tube and seeing if there's any scale in there. If that doesn't work, I am going to tackle the bottom. But if I remove that pipe, I am going to have water pouring out of the boiler. So that's going to be a bigger job.

J

LS,
I have experienced the same thing with my Cimbali jr. The problem is caused by clogging of the lower tube with scale debris. Descaling will probably not work. You have to disassemble the sightglass and purge the lower tube.
Cheers, TY

Hello:

jknotzke wrote: Thanks for the suggestion.

You're welcome.

To me, everything points to a blockage of the vertical accesory exiting the boiler at the bottom, probably extending to the lowest part of the horizontal tube going to the level indicator assembly. (red lines indicate where you can expect to find the deposits)



This the lowest part of the boiler system and as such, the place where everything eventually settles.

But there's only one way to be 100% certain. =-)

jknotzke wrote: But if I remove that pipe, I am going to have water pouring out of the boiler.

Well, before touching that tube you should consider emptying the boiler first.

To do that, use the 'gas tank' method I described in my previous post but please remember to unplug the machine before doing anything inside it.

Please do post your results, photos of the tube when removed will be appreciated.

Cheers,

CIV

Hello:

jknotzke wrote: ... start by taking apart the top tube and seeing if there's any scale in there. If that doesn't work, I am going to tackle the bottom.

So ...
¿How did it go?

Cheers,

CIV