High water pressure alarm issues

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Ed
Americano
Posts: 8
Joined: Wed Apr 05, 2017 8:18 pm
Location: Toronto

High water pressure alarm issues

Post by Ed »

Hi everyone,

I'm wondering if anyone is familiar with this particular issue:

I'm the new owner of a used LS S1 Dream. So far I'm very happy with it, the previous owner appears to have taken good care of it. So far (knock on wood), I have only had to clean out the flowmeter of some small brass shavings. Since then the one minor issue I'm having is intermittent high water pressure alarms. When I run the grouphead or press the shot button, the pressure sensor shows about 2.2bar line pressure during the pre-infusion, then 8.5-9bar during the shot or backflush. So those numbers all seem fairly normal based on the plumbing setup (see below), and that the pump seems to be properly adjusted for brewing pressure.

In terms of plumbing I have the machine set up on a 3/8" John Guest waterline. From the main house water line, there is a JG shutoff valve, then 10" softener, 10" carbon filter, another shutoff, then a pressure regulator (50psi non-adjustable regulator, with integrated check valve). Then 3/8" JG tubing connected to the the stainless braided line to the machine.

The high pressure alarms come often when the machine sits for a period of time after a shot, or first thing in the morning while it's warming up before use. Sometimes in the morning I will find it at 6-7bar or higher. When I run the grouphead the pressure immediately returns to line pressure (~2.2bar). Sometimes while the machine is idle the reading on the screen will stay in the 3-5bar range. It never seems to sit down at the line pressure.

If anyone can point me in the right direction in terms of troubleshooting this, it would be much appreciated. I can see from the manual diagrams that the pressure sensor seems to sit between the pump and an internal check valve. I often see the pressure start to climb after a shot on the machine for no apparent reason. The pump is not running, and the brew and steam temperatures are close to their setpoints.

The one forum thread I found similar to this issue is here:

http://s1cafe.com/viewtopic.php?f=72&t= ... arm#p21330

It sounds like a very similar issue but I would say that in my experience, pulling a shot only temporarily lowers the pressure sensor reading, then it typically rises after.

Any suggestions are greatly appreciated!

Ed
La Spaziale S1 Dream, Nuovo Simonelli MDX On Demand
goodboyr
Barista
Posts: 255
Joined: Thu Jan 10, 2013 10:05 pm
Location: Canada

Re: High water pressure alarm issues

Post by goodboyr »

I was the op on that thread. Turned out to be the pressure regulator. I changed it to the brass Watts model. I think the cheaper ones do not relieve pressure back the other way and bottle up the system. Also, if your brew temperature sensor begins to fail, typically they start to read low, causing the actual brew temperature to rise. This exacerbates the problem. You can tell this is beginning to happen when you see the brew water flash to steam. So, in summary, get a high quality watts brass regulator, and keep your eye on your brew temperature sensor.

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Bob
La Spaziale Dream and Baratza Sette 270W
Ed
Americano
Posts: 8
Joined: Wed Apr 05, 2017 8:18 pm
Location: Toronto

Re: High water pressure alarm issues

Post by Ed »

Thanks Bob for the quick reply about your old post. I will look into the higher quality regulator. The other thing I noticed last night was small air bubbles in the small lines running to the pressure sensor and boiler pressure gauge. This could have occured when I was plumbing the machine and it lost its prime which may have introduced air into those lines. I'm not sure if this would contribute to the issue, and I'm also not sure how involved it would be to clear the air in those lines as water doesn't flow through, it just stays in there to supply the sensor/gauge. Thanks again!
La Spaziale S1 Dream, Nuovo Simonelli MDX On Demand
goodboyr
Barista
Posts: 255
Joined: Thu Jan 10, 2013 10:05 pm
Location: Canada

Re: High water pressure alarm issues

Post by goodboyr »

I don't think the bubbles are the issue.

Sent from my SM-G900W8 using Tapatalk
Bob
La Spaziale Dream and Baratza Sette 270W
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