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Hi, I have a Bezzera BZ07 and when I attempt to pull a shot I only get steam coming out of the group-head. I've taken the cover off and have started to doing some investigation as to what could be wrong. I've noticed that there is a little spring with a plastic fitting sitting in the hose between the 'Pump Priming Valve' and the 'Y' splitter that goes back to the tank. Can anyone tell me where this part might have come from as I'm guessing I need to replace it.

Location Found:


Mystery Part:


Thanks,

Brian

That's weird. Not 100% sure, but believe it would have come off the pump priming valve, so thinking that's really the problem and need to replace that. Also thinking the tubing is standard 6mm or 8mm silicone tubing that you can get many places. Is it kinda squishy?

The pieces you have shown seem to be a check valve of some sort. you found it in the actual tubing itself?

This is the PDF with the parts diagrams It looks like part of the OPV.

your pump priming valve broke (what you see is its internals). exchange it.
alternatively it might be possible to skip this valve completely.

HoldTheOnions wrote:That's weird. Not 100% sure, but believe it would have come off the pump priming valve, so thinking that's really the problem and need to replace that. Also thinking the tubing is standard 6mm or 8mm silicone tubing that you can get many places. Is it kinda squishy?

Hi, the tubing is squishy. However, I was able to remove it from the 'Y' and it seems to be undamaged so I'm hoping I can re-use it.

Thanks,

Brian

jbentham wrote:The pieces you have shown seem to be a check valve of some sort. you found it in the actual tubing itself?

Yes, I found those parts inside the actual tube

If this valve doesn't show to be related to your steamy group problem, you should check the group thermostat - if it's permanently closed the group can go up to 140-150C in my experience...

this valve is totally related to the problem as it vents water back to the pump inlet in case the pressure/flow is too low (to allow the air to be expelled and prime the pump at free-flow condition). as its side outlet is broken, this valve now vents everything (because the side port has lesser hydraulic resistance than the straight way that happens to have one-way valve on the output) back so there is no water entering the HX.

just replace the priming (Ulka S11) valve.

Hi Kolu, I'll remove that valve and order a new one. Given that the machine is 9 years old, are there any other parts that I should replace or order while I have it taken apart ?

Thanks,

Brian