New Rancilio Silvia intense whistling noise when starting

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#1: Post by pelletim »

I purchased a Rancilio Silvia espresso machine 2 weeks ago.
I set it up correctly. I didn't have any issues with the machine the first few days.

However, this week, every time I start the machine in the morning, it makes strange noise (hissing, whistling). It's very loud. Enough to hurt your ears. If I open the steam/water valve, the sound stops.


Any advice ?


Team HB

#2: Post by JRising »

It can only be the expansion pressure escaping over the OPV, but it isn't normal for Silvias to make that noise just by heating up.
You can often find a "harmonic spot" when adjusting the OPV with the pump running against a blind filter, it goes away if you adjust just slightly higher or lower.

You should talk to the seller, let them know that the OPV is making a harmonic noise as expansion pressure escapes the expansion valve, either ask them if they would adjust your OPV for you to see if you can make it go away, or have them tell you that you aren't going to void a warranty by adjusting the OPV slightly. Perhaps adjusting it down below 8 bar, then back up to 8.8 or 9 bar will set the spring in a way that it doesn't "sing".

pelletim (original poster)

#3: Post by pelletim (original poster) »

Thank you for the detailed explanations. Much appreciated!

Is it true the valve comes out of the factory set at 12 PSI?

Team HB

#4: Post by JRising »

In my mind, no, a Silvia will probably be about 10.25-10.5, but feel free to prove me wrong, I haven't measured a brand new Silvia in a long time. I did a PDI on both a Silvia Pro and a Pro X yesterday, didn't write down where the pressure was, but it didn't surprise me, so probably a bit above 10...

A Bianca is factory set up in the 12 bar range (on reservoir).


#5: Post by pratik3805 »

I had the same issue with my Silvia. I lowered the pressure via the OPV and it was gone. Try it if you can.


#6: Post by Roco2019 »

Hi Pelletim,

Just following up on your harmonic issue with your Silvia because I ran into the same problem with mine. It makes an annoying whistling harmonic sound unless I keep the steam knob slightly loose.

When I contacted the place i bought it from they replied the expansion valve takes some time to get broken in, but it's already been 11 months since I bought it.

Did you loosen the opv a bit? Did they let you tinker without voiding warranty? I'm planning to once I have a chance.
LMWDP #697