Rancilio Silvia pressure seems to be low today. Went to make my usual espresso but drip was very slow. Tried 3 more shots same problem. Hot water is not the problem, nor steam, though steam seems to come out with less pressure. Questions: Could it require cleaning, is it the pump, or something else.

Your help is greatly appreciated.

Christian

"Seems" low is different from "is" low. Did you try to adjust the grind?

Yes I did adjust the grind, even though it's the same coffee and grind setting I have been using for months. Does the Pump control how much pressure water is pushed to pull a shot?

The maximum pressure achievable in any machine is the maximum pressure that the pump can develop, but that needs to be regulated. There is a bypass of some sort, usually referred to as an over-pressure valve (OPV) or pressure relief valve that opens and returns excess water to the reservoir in some machines, or in others it sends it to the drip tray. It could be that this valve has some scale or other foreign matter in it that is causing it to leak. In the Silvia, this valve is mounted to the boiler and has the return hose (the shorter hose) that goes back to the reservoir.

How old is the machine? More recent Silvia's have an adjustable OPV and others (older models) it requires disassembly to deal with it.

It's a newer machine, about a year old. I will try di-scaling to see if that fixes the problem.

Thanks,
Christian

I believe your dispersion screen is clogged up. Remove your dispersion screen (36) and soak in hot Joe-Glo or Cafiza for about 30 minutes and clean with old toothbrush.

Took it out and it looks gunky, so it's soaking now.

Thanks,
Christian

Thanks everyone for your help. I just finished with cleaning machine and the dispersion screen. Now it works better than new. Haha, at least a 1000 times better than yesterday.

Christian

If your Silvia's group got so bad it was restricting flow reading Espresso Machine Cleaning Why, How, and When is in order. Day in day out shot quality will thank you too.