I've had my Silvia for about 18 months now, and recently while frothing I noticed that the steam pressure is much lower than original. What maintenance steps can I do to get back the steam pressure? Could it be caused by scaling build up?

I suppose it could be scale buildup but I doubt it. If you fill in your profile and let us know where you're from, someone in your location might chime in and complain about the unusually hard water in your local or perhaps, offer hands-on help.

I just ran a small test on Silvia to check and compare water flow rates from both the grouphead and the steam wand. I flowed 11.25 ounces in 30 seconds from the grouphead and 11.0 ounces in 30 seconds from the steam wand - both with about 150 F water. The average of these rates (658 cc/min) tracks pretty close to the published flowrate of the Ulka pump telling me that my steam wand is not suffering any blockage.

How do your flow rates compare? If your steam wand shows a lot less flow, unscrew the tip and try again.

Another problem could be a malfunctioning steam thermostat. Assuming you start steaming when the "ready light" goes out, how long does it take for this light to go out after you hit the switch? I'm thinking it should take about 1 minute but this I haven't timed. Is the "ready light" steadily on during the heat-up to the steaming point?

Eric S.

edit - timing for steam light is 66 seconds for me.

It takes 2min 10sec for steam ready after doing a pull. To froth 8oz of milk to 160deg then takes 90sec.

OK, well obviously the time you are reporting is excessive. Did you do the water flow test and, if so, what are the results?

Eric S.

I timed 8 oz in 23 sec from the grouphead (28 with filter attached), and 8 oz in 22 sec from the wand. This flow rate is about the same as yours, but my water temp was at 180 deg GH and 172 deg wand.

Well, that flowrate test removes the possibility of something partially clogging the steam nozzle. Assuming the heating light is constantly and brightly lit as you approach steaming, a temporary fix to improve the steaming would be to start the steaming process prior to the light going out. If the 2 min 10 sec wait is fairly consistent, I would shoot for the 2 minute mark to begin steaming and the light should stay lit during the entire procedure.

Silvia's heating element has a cold resistance of 15.1 to 15.2 ohms if you have the tools and feel comfortable measuring it. I mention this only because of an outside chance there is something amiss there.

But back to your original thought about scale - it's possible that the heating element has some build-up and a descaling operation would help out. In that event, do a search on this site using the keyword "descale" and plenty of info is available. I would run the descaling solution through the steam wand using the hot water switch, operating the pump for 30 seconds on, 60 seconds off. I would use Cleancaf by Urnex and follow the package directions for mixing & flushing.

Skol,

Eric S.

There are reported instances of fault currents from failing heating elements in Silvia's. This is a possible explanation (there are many others, too) for what seems to be low energy output from your heater. Since a ground fault condition would be potentially dangerous, if the machine is not plugged into a GFI outlet/circuit it might be a swell idea to do so now.

Jim

Ya know Jim - I agree - i.e. I would put some monies on a leak to ground here. SigCool - If you do have a leak to ground the machine should trip a GFI circuit instantaneously.

I just can't see scale causing a 130 second climb from brew to steam even though SigCool is in Ann Arbor where water hardness is twice the recommended level for espresso.

Eric

I plugged it into a GFI outlet, and went through a complete heating cycle and steaming cycle. It worked as normal and did not trip the outlet. I did verify the outlet also with a tester.

I checked the resistance of the heating element, and it seems ok at 15.6~15.7 ohms...

I don't know what else would cause the issue, it just seems like there is low power output. What next?

Well, I then suppose we are back to what you proposed to be the problem - scale.

Assuming you have a high confidence level in the time to go from end of brew to steam light off - 130 seconds, do a descaling with CleanCaf by Urnex and I would recommend you run the solution through the steam wand only - even remove the tip. The rationale here is that if there is enough scale to cause this heating problem, I would not want any "chunks" coming off to clog the brew passageways. Granted, the descaling solution/operation is designed to dissolve the scale to a great extent, I would not take any chances here.

At the risk of sounding like a broken record, I believe it is important to have a high degree of confidence in this "130 second" time period so that you can do a reasonable before/after comparison. For example - suppose after the first descaling op you go from 130 seconds to 100 seconds. That not only tells you that you are on the right track but that you also have a little ways more to go.

Skol,

Eric S.