My Silvia is about 2 years old, and has the newer, adjustable OPV. I have the gauge from 1st Line. I find that if I adjust the valve until the gauge reads around 10 bar, although brew performance seems fine, the machine cannot generate sufficient steam. Returning the setting to about 11 bar on the gauge corrects the problem. Maybe the gauge needs calibration? On the other hand, I have read that the Silvia ships with the OPV at 11 bar. Anyway, if you go too low, you kill the steam.


PS added by moderator: Split from Adjusting Rancilio Silvia brew pressure (OPV).

rickrobin wrote:I find that if I adjust the valve until the gauge reads around 10 bar, although brew performance seems fine, the machine cannot generate sufficient steam. Returning the setting to about 11 bar on the gauge corrects the problem.

I don't see how the OPV setting for brew pressure and steam performance could be related.

HB wrote:I don't see how the OPV setting for brew pressure and steam performance could be related.

I don't either, but there it is. I would guess that the OPV senses boiler pressure, and that setting it too low causes it to open before there is sufficient steaming pressure. Unless the valve, or a T'stat, got kacked in the process of my efforts.

Actually, I've had to dial it up to 11.5 to restore full steaming capability. Shots are very good. So it seems like there is a threshold beyond which the OPV is ineffective on brew pressure, but begins to strangle steaming performance. With my machine and gauge, anyway, that threshold is 11.5 bar.

Thanks for the help, guys - much appreciated. Yeah, apparently it was just coincidental that the steam was temporarily OK after I adjusted the valve up. I put it back to 9.5. Now the question is, what's happening with the steam? The stat isn't shorted. Maybe it went out of adjustment? although the machine gets way hot physically with the steam switch on; but there's only strong steam for a few seconds before it becomes anemic. I just descaled a few weeks ago. Guess I'll try doing it again. One thing I notice is that the plastic insulator on the wire clip that connects to the boiler is burnt to a crisp. Been that way forever though. ?

I think it's the steaming stat. The steam is only 150 degrees. After a few seconds I can hold my hand in it. S

It's about 2 years old.

Aaaaack! That looks really bad.

Theory: something local to that connection is creating extra resistance, which in turn is generating extra heat. The connection might be bad enough that it is limiting the current available to the heating coil (a possible explanation for your poor steam).

Observe that the corresponding connector on the other heater tab is still in good shape. Both of these should carry the same current and be exposed to the same temperature. So there's clearly something out of the ordinary going on at the burned side.

Replace the crimped connector. If the burning repeats, then there's a problem with the heating coil.

Jim

EDIT -- Sorry, Eric, didn't see your reply had already been posted.

Thanks Eric and Jim. I spoke with a tech at Chris Coffee, who concurred with you guys about the connection. I replaced the connector, but steaming is not improved. The Chris guy didn't think the heating element would be bad if the brewing performance is good; he did think the steam stat was probably bad, so I ordered one, for a big $9.50. (Not only are they super helpful, but their parts prices seem to be the best around, btw.) Maybe the arcing connector took out the stat? Anyway, I'll be sure to post an update, FYI. Thanks again for your help!

Rick

That should probably be replaced with a high temp nickel plated steel faston, if you can't find one ask me privately and I'll see if I have one to drop in the mail. I think I had to buy 100 when I had the same problem on my Capresso drip machine.

Ira

rickrobin wrote:I find that if I adjust the valve until the gauge reads around 10 bar, although brew performance seems fine, the machine cannot generate sufficient steam. .

I think I have the same problem. Today I replaced my RTD probe with a K-type thermocouple for my PID, and adjusted the PID. Silvia now generates significantly less steam (the steam thermostat opens at 275* instead of the 290* previously).

2 steps forward, 1 step back...
Any ideas here before I quit and just go to Murky on my way to work every morning instead?
Thanks
Peter

Upon further review, I think that it is a faulty steam thermostat. The temp that it opens varies widely (a minute ago, it opened at 290*, but I just tried it again and it opened at 230*).

The machine is a few years old. Instead of ordering a new thermostat, I may just install the alarm steam control. Any thoughts on where to buy the diodes?


Thanks

Peter

Well, I replaced the steam stat - no difference. I used to be able to open the steam valve, like, three times in a row for a few seconds each time to get nice, dry steam, then froth 4 to 8 oz of milk without a squeal. Now if I bleed it like that I can't do anything. It has full pressure off the bat, but no staying power. If I bleed it a few times while it's heating (instead of waiting till the light goes out) it's usually alright, but I didn't HAVE to do it that way before. As it is now, if there's head water when the light goes out and I bleed till it's dry, I have to blow the whole charge and let it cycle again - whereupon it steams like a champ.

There's no problem with brewing pressure/temp - but I did have to go back to 10 to 10.5 bar on my gauge. I assume the gauge is out of calibration, because it brews beautifully now, where at 9.5 it was anemic - pucks were bone dry. (15g.) Does this make sense?

All three stats all show full continuity when tested out of the circuit, as does my clip repair, as does the heater coil, minus the correct 16 ohms or so.

So what the *&^%$ ? If the coil were encrusted with scale, would it produce these symptoms? I thought I had the water thing together, but since it seems to be the only thing left, maybe not. You think?

rickrobin wrote: If the [heating..?] coil were encrusted with scale, would it produce these symptoms? I thought I had the water thing together, but since it seems to be the only thing left, maybe not. You think?

That was my next guess. You say that you have had it for years? What water are you using and how often has it been descaled? If the answers are "tap" and "never" then get some "Dezcal" and have at it. Also, remove the steam tip from the wand and check to make sure it is clean.

rickrobin wrote:If I bleed it a few times while it's heating (instead of waiting till the light goes out) it's usually alright, but I didn't HAVE to do it that way before. As it is now, if there's head water when the light goes out and I bleed till it's dry, I have to blow the whole charge and let it cycle again - whereupon it steams like a champ.

That sounds pretty normal to be honest. You'll get much better steaming performance at temperatures above 275F. The light usually goes off at 290F to 300F. The steam thermostat will allow the temps to drop into the 250's before it switches back on.

rickrobin wrote:There's no problem with brewing pressure/temp - but I did have to go back to 10 to 10.5 bar on my gauge. I assume the gauge is out of calibration, because it brews beautifully now, where at 9.5 it was anemic - pucks were bone dry. (15g.) Does this make sense?

No it doesn't . You would probably have had to use a slightly coarser grind with the 9.5 bar setting. But besides that I would not expect any significant differences in the way a shot is pulled.

rickrobin wrote:So what the *&^%$ ? If the coil were encrusted with scale, would it produce these symptoms? I thought I had the water thing together, but since it seems to be the only thing left, maybe not. You think?

I'll piggyback on Randy's suggestion to check the steam wand. You may have something clogging it. The tip comes off (standard right hand thread), but be gentle.

Just for grins, put a stopwatch on your heater. Time it from when you flip on the steam switch until the orange light goes off again. Should be around 90 seconds. If the heater is badly scaled then your machine might take a lot longer.

Jim

Thanks very much Randy and Jim!

The steam wand is clear. I'm very good about that.

Water: I have an elaborate water treatment system on my well that removes the iron and magnesium, and normalizes the ph. But it doesn't remove calcium, which is prodigious. My solution has been to use a Brita, strictly, for brew water. (Reagent strip shows about 100ppm of hardness shortly before I change the cartridge.) I've been descaling with citric acid (10 grams/liter) every three months. Since the hardness in the Brita water is probably all calcium, maybe this isn't often enough. But I don't see much of anything in the descale water, and there are no other symptoms of scaling that I've noticed.

Jim - I know that how I described it sounds fairly normal, but I assure you the steaming capacity has changed markedly. As you know from the title of this thread, this seemed to happen exactly when I was adjusting the OPV (I know, I know - whatever!). Before that the only thing I noticed was that sometimes there would be more head water than usual - which did result in insufficient steam, as now, if I cleared it all. But that only happened occasionally, and I chalked it up to the vagaries of the beast. Then the apparently arcing contact situation seemed a more than likely explanation.

As for the OPV adjustment, I had to grind 3 NOTCHES coarser on my Tranquilo, and it hardly seemed to matter - it just wasn't right. The difference between 9.5 and 10 on the gauge was dramatic - like throwing a switch. (OPV sounds suspect, eh? Possible reason follows, below.) The gauge is steady, and reads exactly the same a day later, hot or cold. The pump holds pressure, and the 3-way valve opens. Anyway, at 10.5, the espresso is smooth, flavorful, and crema-laden.

But here's one more crazy thing for you: When I was adjusting the OPV initially, I didn't get the drain line loose enough, and it kinked. Then, in the process of trying to pry it loose, I tore it; so I snipped it, put it back on, and it's fine. But when it was kinked, the OPV would squeal when brewing. (That's why I went back in and discovered the kink.) Also, clearly due to the restricted line, my pressure gauge would fibrillate like crazy, and the lowest I could get it was about 11.5. But - and you're really gonna think I'm nuts now - the coffee the thing made under those circumstances was the creamiest, richest, densest, most delicious stuff I ever had, anywhere! Maybe it was just the blend I was using at the time - home-roast which, naturally, I immediately ran out of. Or maybe I've made the greatest discovery in espresso history! : )

I don't know what I'm smiling at - this business is driving me crazy, already!