La Marzocco GS3 idling pressure - Page 2
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bryston (original poster)
Yes, when I turn it ON it will go up to 12 bar, then it will drift down to line pressure over 2 hours or so while it is still ON.
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Jake_G
- Team HB
Hey Jef,
I got your PM regarding the check valve near the HX that believe could be the culprit.
Here's what I believe you were pointing out:
Annoying that the check valve doesn't have a number, but they're all the same. The check valve threads into the mixing block labeled 12, and it is shown threaded into the block between the number balloons for items 16 and 17. Is that what you're thinking could be the problem?
If so, while possible, it is unlilely to be causing the issue you are seeing unless the check valve in the pump has also failed. That check valve is item 5 below:
Far more likely is that your conical valve needs service. The best way to check is to hold a spoon up to the shower screen and see if you get a fogging of steam on it. If you do, your group needs service.
If not, I'd honestly recommend you wait a bit before worrying too much about the problem.
True, it is not as-designed, since the check valves should keep the brew boiler pressurized at some elevated pressure at idle. But if it isn't leaking, there really isn't anything terrible that is going to happen from a 3 bar resting pressure. If you can spot the culprit, by all means, address it. But I wouldn't spend too much time or money chasing this specific ghost if it doesn't want to be found. Just my opinion.
Cheers!
-Jake
I got your PM regarding the check valve near the HX that believe could be the culprit.
Here's what I believe you were pointing out:
Annoying that the check valve doesn't have a number, but they're all the same. The check valve threads into the mixing block labeled 12, and it is shown threaded into the block between the number balloons for items 16 and 17. Is that what you're thinking could be the problem?
If so, while possible, it is unlilely to be causing the issue you are seeing unless the check valve in the pump has also failed. That check valve is item 5 below:
Far more likely is that your conical valve needs service. The best way to check is to hold a spoon up to the shower screen and see if you get a fogging of steam on it. If you do, your group needs service.
If not, I'd honestly recommend you wait a bit before worrying too much about the problem.
True, it is not as-designed, since the check valves should keep the brew boiler pressurized at some elevated pressure at idle. But if it isn't leaking, there really isn't anything terrible that is going to happen from a 3 bar resting pressure. If you can spot the culprit, by all means, address it. But I wouldn't spend too much time or money chasing this specific ghost if it doesn't want to be found. Just my opinion.
Cheers!
-Jake
LMWDP #704
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bryston (original poster)
Thanks, I just read your response, there is no leak at the group head( spoon test normal).
If the check valve at the pump is ok , and the one near the HX leaking it will start slowly over filling the steam boiler , will be very hard to notice .
The problems seems some what better the last few days, I did not do anything.
I ordered 2 new check valves but I did not replace any.
And finally some one from La marzocco spoke to me and told me half way while I was explaining the issue it is normal, he said after a year I may notice that as there could be a small leak in the check valves, he said the new valves should last 6-7 years before needing replacement.
He seemed very familiar with the issue.
As for now decided not to do anything, as what you told me goes with what Lm said.
Thanks for your help.
If the check valve at the pump is ok , and the one near the HX leaking it will start slowly over filling the steam boiler , will be very hard to notice .
The problems seems some what better the last few days, I did not do anything.
I ordered 2 new check valves but I did not replace any.
And finally some one from La marzocco spoke to me and told me half way while I was explaining the issue it is normal, he said after a year I may notice that as there could be a small leak in the check valves, he said the new valves should last 6-7 years before needing replacement.
He seemed very familiar with the issue.
As for now decided not to do anything, as what you told me goes with what Lm said.
Thanks for your help.
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Jake_G
- Team HB
Glad to hear it.
Just so you know, there are two check valves in between the tea water mixing valve and the steam boiler that would need to both be leaking in order for the steam boiler to slowly fill up. This actually happened frequently enough in the early machines with a single check valve that they added a second one.
I agree with LM that you have nothing to worry about for now.
Cheers!
- Jake
Just so you know, there are two check valves in between the tea water mixing valve and the steam boiler that would need to both be leaking in order for the steam boiler to slowly fill up. This actually happened frequently enough in the early machines with a single check valve that they added a second one.
I agree with LM that you have nothing to worry about for now.
Cheers!
- Jake
LMWDP #704
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bryston (original poster)
I know what you mean, but when the water slowly flow back to the cold water line( the stainless ) it will make it to the steam boiler , the valves at the steam boiler they do not have to be leaking as that will be the normal direction to fill the steam boiler .
Correct it me if I am wrong, I would like to know.
Correct it me if I am wrong, I would like to know.
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Jake_G
- Team HB
The only two paths for water to get to the steam boiler are through the pair of check valves mentioned before or through the boiler fill valve.
You'll know if either of those are leaking, because your safety valve on the boiler will open and flood your counter with an unending supply of water coming from your water connection. It's a bad scenario, hence the extra check valve.
You'll know if either of those are leaking, because your safety valve on the boiler will open and flood your counter with an unending supply of water coming from your water connection. It's a bad scenario, hence the extra check valve.
LMWDP #704
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