The S1 Cafe - Helping Your Espresso Dreams Become Reality

I was getting a high pitched whine from the group boiler whenever the heating element kicked in and it was nearing the set temperature. I was also getting some water dripping at the same time from either the group head or the 3 way valve outlet. I tried back-flushing alot, also with Cafiza and was able to make it intermittent but the noise and dripping came back. This was a loud whine you could hear two rooms away. I decided to check the expansion valve setting because it seemed to me that on heating the pressure might get high enough to force some water past the 3 way valve and create the whine. So I followed the procedure on adjusting the 3 way valve and found it was cranked tight! I loosened it nearly 3 full turns to get it to drip at 12.5 bar. Glory be - the whine stopped. Thanks again to Charles for the information on this site that helped me fix this.

Is this problem related to what happened back in January to your machine?
From what I recall, it was the infamous brass shavings syndrome last time.

I remember some forum members describing something like this a year or so ago. They called Chris Coffee and were told to unscrew the expansion valve 2-3 turns and this fixed the issue in all cases.

It seems intuitively wrong but you can't knock success!

Niko, No different critter. That was the flow meter. I did take apart the expansion valve and only found some corrosion.
Chas, It would be interesting to know what the pressure was spiking to with the expansion valve set that tight.

The expansion valve was way tight on my VII when I received it. I had to unscrew quite a bit also to get it to open at 12.5bar. With it properly adjusted I get very little dripping. Perhaps a few drops after I pull a shot. However, before the adjustment I would get some drips every time the boiler cycled.

I just received my VII from Chris in early April; should I check my expansion valve? Since they say that they check and adjust every machine I have been presuming that these adjustments should be correct without any double-checking or adjustment?

Thanks for any advice...

I would leave it alone unless your machine is leaking quite frequently.

My V2 makes a whining noise as well, but it only happens when the steam boiler kicks in. I always assumed it was the fan inside the machine. I don't get any leaking in the OP valve. Does this sound like the same thing?

-Joe

can you post a video with sound?
we can listen for it and tell you...

Here is a link to the video (I hope I did this right):

http://karatevid.com/clips/noiseV2.wmv

The noise is kind of faint on the video. It sure sounds like the fan to me.

-Joe

Niko wrote:can you post a video with sound?
we can listen for it and tell you...

That little whining sound is the fan, the other lower frequency sound is some kind of interference the camera is picking up while the steam boiler revs up.
I think everything is OK.
Have noticed anything else odd, such as boiler pressure getting a little higher than normal?

So after replacing the pump, and attempting to calibrate the expansion valve per Chas' instructions, I got the same whine whenever the boiler would refill.

Anyhow, now I am at this situation:

At it's current position (or tighter), it does not drip, but will whine when refilling. If I go a 1/4 turn looser, the whining stops, but a cup under it reveals that within an hour or so, about 2 ounces has dripped (just sitting at idle).

I guess my concerns are:

1. My calibration is out the window, so should I try to recalibrate? If not, is there any risk or consequences?

2. If I leave it in the position where it does drip, but does not whine, is there any risk or consequences?

3. Seeing as how I have had numerous brass shavings throughout my system, does it make sense to take apart the expansion valve? If so, anything I need to do other than unscrew it (loosen it)?

Mine leaks as we speak...
Not sure why but it constantly drips whenever the group light flashes to indicate that the element is on. There was a time when I would make some adjustments to stop the leaking but it hasn't bothered me enough to mess with it. My old S1 does not leak at all but that machine is not plumbed in the same room.
As for that whine, I'd like to hear it...
can you post a video with sound? Maybe mine does it too but it never dawned on me. It does sound like your adjustments are either too far North or South.

Do you have any ideas, Chas?

There should be a thread here somewhere on this unless it was discussed during the missing 6 months in 2006. Whoever had that happen first called Chris Tech Support and was told to give the expansion valve about 1 1/2 turns. However, I don't remember which way you are supposed to turn it, but that seemed to be the definitive fix.

For those that have never removed the expansion valve, you may want to check it. It is a pretty basic design. Inside the valve is just a spring with a rubber disk attached to the end. The spring pushes this disk up against the end of a pipe that is a little smaller in diameter than the diameter of the rubber disk. It is possible to get some crud between the end of the pipe and the rubber disk or the rubber disk might be hitting the pipe off center. Cleaning this out and checking the state of the rubber disk is worthwhile.

The caveat is that it takes a bit of effort to screw the valve back on because you have to push up hard against the spring while getting it threaded back on. This pushing is done at a fairly awkward angle so it make take a few attempts to get it started. Not a real big deal.

Then any time you take that valve apart you have to readjust the release pressure on the valve (12.5 bar) and then readjust the group pressure. This is documented on the S1 site. Just use the "Go to S1 Web Site" at the top of this page.

I had already taken it apart, and really could not find anything amiss.

Well it sounds like I have a worn seat (the rubber disc inside the expansion valve), since mine leaks all the time and should only drip or leak when group boiler is refilling. This is all according to Jason at Chris' coffee.

The problem is that literally the point at which it stops whining is the point at which it starts leaking, so there is no happy medium. Should have the disc this week, and will report back. I am pretty sure this will fix it, and of course I want this fixed before I sell it.