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The valve body pressurestat is hissing... why?

Postby GriffDeLaGriff on Sat Jan 05, 2013 3:29 pm

So this hiss/drip/hiss started some time ago and I just used the stethoscope-method to find where it comes from.

It comes from this, that I think is the pressurestat.
Image

On top of it is a tube.
Image

This tube goes into a chute down to the driptray. The chute is hot from the boiler. It almost constantly comes water from this tube and it drips down the warm(hot) chute and the hiss comes from the impact of the water on the chute.

If I squeeze the tube the sound is gone, if I release - it comes back.


I didnt have this before. Basically I want to know:
x Is there any danger (with the explosion in the cafe fresh in my mind and having now 2 kids in the house)
x Is it normal?
x If not, what can I do? Clean....replace?
x Should I continue to use the machine? Or let it be.

I also have a youtube film of it, but it came out pretty bad since there is some background noise which makes it sound as there is a noise (the room) even when I squeeze the tube but its really silent irl.



Ignore the children in the background :mrgreen:
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Postby JimH on Sat Jan 05, 2013 6:02 pm

The p-stat is on the side, the valve body appears to include the boiler safety valve. The hiss is from steam escaping from the safety valve. There are a couple possible reasons, it has an obstruction that is keeping it from closing completely, or your boiler is running at an exceedingly high pressure. So check the pressure gauge, if you are above 1.8 bar (the pressure listed on the side of the valve in your picture) then you definitely need to adjust the p-stat. If the boiler pressure is below 1.8 bar, you probably need to either disassemble and clean the safety valve or replace it.
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Postby GriffDeLaGriff on Sun Jan 06, 2013 4:41 am

Ok thanks.

I will check it out, I think its below 1.8 so I may have to disassemble.

But if it is 1.8 or above, do I adjust the pressure by just turning the screw on the p-stat? (not visible on the picture but there is only 1 screw on it)
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Postby GriffDeLaGriff on Sun Jan 06, 2013 10:00 am

It doesnt go above 1.5 so I took it apart to inspect/clean.

Everything looked "clean" apart from the top "valve" that the tube producing the hissing comes from.
Looked like something white inside so I cleaned it with a needle and its now in a cafiza-bath for a while.


Something happened tho, that i need to ask you guys about.

When I tried to get it from each other it was very stuck and I accidentally dented the pressurestat. The black round housing - on the back - now has a small hole in it. It doesnt look like there is anything inside from this side (looks empty) so can I just epoxy the piece back and use it or do I need to get a new one?

Image
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Postby erics on Sun Jan 06, 2013 10:15 am

Epoxy it back in with a very minimal amount of adhesive.

Your machine is fitted with a manifold assembly with all of those various components normally having their own boiler connections . . . saves space and $$. What is leaking on your machine is the top fitting which is the vacuum breaker valve - not uncommon.

Remove the valve and soak that assembly in white vinegar for 30 minutes, rinse with water and reinstall.
Skål,

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E-mail: erics at erols dot com
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Postby slybarman on Sun Jan 06, 2013 10:38 am

GriffDeLaGriff:

Is the machine a Cuadra:

Mine started to hiss a bit from that valve recently as well. Have you descaled recently?
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Postby GriffDeLaGriff on Sun Jan 06, 2013 10:49 am

Alright thanks alot.

Yes it is a Cuadra and no I havent descaled it at all.

There is a Red Goat coffe just outside my window and I asked them about it - they said their machine guy have gone over their machine and it hasnt got anything in it.


However, this white stuff on top on the valve might be lime so .......what is the best way to descale?
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Postby slybarman on Sun Jan 06, 2013 11:01 am

In general terms:



If Eric suggests soaking the valve in white vinegar, then that might be the way to go.
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Postby GriffDeLaGriff on Sun Jan 06, 2013 1:21 pm

Thanks.


Well, I dont have any vinegar, but cafiza did the trick.
The top valve now have a much bigger hole then before. It was kinda clogged with white hard stuff.


I seem to be out of epoxy tho, so have to wait until i get some, for the test.
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Postby GriffDeLaGriff on Sun Jan 06, 2013 2:39 pm

But as i re-read the posts, I have been given 2 different answers on what valve this is.

So is it the vacuum breaker valve or the pressure relieve valve/safety valve?

If it is the vacuum breaker, then where is the safety valve on my machine?
On the bottom?

Both have a spring and some sort of seal, the lower one also have a plastic end that fits to a tube and it says "ulca" on the plastic end.
Both have tubes that goes into the chute down to the driptray and they are accompanied by a tube from the OPV.


And also lol but I kinda forgot how this would fit together.
Im pretty sure it is like this, but shout if it looks wrong:

Image

(the white plastic is smaller on top and the spring goes around the very top, snug and good.)

Image

(the little square has a rubber seal inside on the top and the spring fits nicely on the bottom)
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