Rancilio Silvia V2 - low flow after pump replacement
I have a V2 Rancilio Silvia, with a MeCoffee PID installed. It's worked great for years, but around 2 months ago the pump (Ulka EP5) gave up. I had the pump replaced (didn't have time to do it, so entrusted it to a shop...).
Ever since the pump replacement, the flow has been low. I'm getting 400-450 ml/min without the portafilter in, rather than the ~600 it should be:
I also haven't been able to get up to the brewing pressures I had with my previous pump (I don't have a pressure meter, but the shots take ~ twice as long to pour the same volume with the same coffee and the same grind.
- Is it possible that the new pump is supposed to be lower pressure, and that I need to adjust my OPV accordingly? Is this a non-problem, and I just need to tweak my machine to accommodate it?
- If not, is there something that might have been missed when setting up the pump, which could be making it less efficient (i.e. something I could fix at home)?
- If not, what's the best way to test the pump, so I can show it's faulty and return it?
Thanks very much for your help!
Ulka pumps should have a certain flow per minute based on pressure. Google 'Ulka pump flow graph' or something similar. You should be able to just measure the flow from the head (essentially no pressure) and verify that it is correct.
if this looks acceptable, then I would start investigating the OPV. A new pump is likely to have a different flow and the OPV may need tweaking.
Inside your group head is a hole, have you clean that, it could be is a bit block from coffee sugars and is not allowing the water to come fast enough. As well if is block probably is why your other pump has fail due to the extra pressure that is working
just check that