Steam boiler pressure oddity

[LeoZ]

I turned my machine on this morning to warm up, and went to the garage to roast some espresso while waiting.
25 mins later, I come in, and the boiler gauge is at 1.5bar and condensate is all over the top of the machine.

I flushed from the steam wand, then ran some water through the grouphead. The pressure stabilized and stayed that way. Then I opened it up so see condensate along the sides of the machine. Of course the vacuum breaker, boiler, etc are bone dry, but thats where all the heat is.

I'm assuming the breaker didnt close all the way and water squirted out. Since water was spraying out, the controller never saw pressure stability so kept cranking until it hit the 1.5bar safety.

Make sense?

Odd that the breaker didnt shut. I recently descaled, but maybe theres some gook around the innerds. Easy enough to change, if this is the source!

Thanks..

[Elbasso]

The boiler is only 60% or so filled. Even when the water in the boiler is fiercely boiling, I doubt that it'll come out through the breaker. I have only experienced this when overfilling the boiler for a descale. No clue what it could have been though. Maybe this answer will help to cross one thing off the list of possible causes.

Cheers,

Bas

[LeoZ]

not sure that this is true.
if the breaker was half open, there is still some pressure in there.
steam can travel for miles when its pressurized.

when normally operating, every time the breaker begins to seat, there is some dribble out of it. ive seen this on both of my machines..

[cannonfodder]

Could have been the vacuum breaker, an internal leak or a sticky pressurestat that overheated the boiler and your emergency release valve popped, which would be my bet. If you have that much condensation inside the case and your pressure is that high, a sticky pressurestat would be my first guess. A vacuum breaker that did not fully close would cause a low pressure situation not a high pressure problem.

[TimEggers]

Of course the vacuum breaker, boiler, etc are bone dry, but thats where all the heat is.

With water loss wouldn't the boiler fill eventually be tripped to top off the boiler? Have you heard the auto fill going at all?

[LeoZ]

Could have been the vacuum breaker, an internal leak or a sticky pressurestat that overheated the boiler and your emergency release valve popped, which would be my bet. If you have that much condensation inside the case and your pressure is that high, a sticky pressurestat would be my first guess. A vacuum breaker that did not fully close would cause a low pressure situation not a high pressure problem.

this makes sense. could be the breaker, and a medium pressure situation. just enough to let it hover and spit out water.

any way to test voltage or resistance across the pressurestat?
i know its a 'common' fail item. simple enough to change.. time for an upgrade?

[LeoZ]

With water loss wouldn't the boiler fill eventually be tripped to top off the boiler? Have you heard the auto fill going at all?

not necessarily. water loss when converting to steam is minimal (in this case)

[TimEggers]

I was curious since you said that the boiler was bone dry. Was that not the case or did I misread?

[cannonfodder]

any way to test voltage or resistance across the pressurestat?
i know its a 'common' fail item. simple enough to change.. time for an upgrade?

There is no real way to test for a sticky pressurestat other than watching the machine and seeing if it overheats. Sometimes it is a one off situation, others it will continually overheat because the Pstat membrane has gotten stiff from scale. You could remove it from the machine and put some descale agent (or even vinegar) in the Pstat and let it sit for a day, rinse it and reinstall just to clean it up.

[cannonfodder]

I was curious since you said that the boiler was bone dry. Was that not the case or did I misread?

I believe he means there was no condensation on the exterior of the boiler. The heat from the boiler would evaporate any condensation but it would collect on the cool internal bits like the shell.

[HB]

i know its a 'common' fail item.

Especially if you run it 24/7. How many years does the pressurestat have on it? Either way, I'd order a new one to have on hand. It misbehaves again, replace it.

[LeoZ]

3 years, give or take?
i vary runtime. sometimes 30mins at a clip, once or twice a day; sometimes on for a week straight

[LeoZ]

well, i replaced the pressurestat with a jaeger. things seemed great for 5 days, then it acted up today again. it had been idle for around 8 hours, and out of nowhere the pressure shot up to 2bar when the release valve kicked in.

now im wondering if its a scale issue. i descale annually, and most recently in April. I'm wondering if i did more harm than good and managed to lodge something in a tube. the tube connecting the pressurestat seemed ok, nothing came out with a small pick.

any other ideas?

thanks!