Old Cremina - New Cap

[espressoperson]

I just got a new boiler cap for my Cremina. It's a new type that has a built-in valve. OPV? The machine now heats up in 10 minutes with no stopping at 7 to 8 minutes in need of a burp like with the old cap. Also, there is no need to leave the steam wand open when the machine is turned off; the lever does not raise up as the machine cools.

The hole in the cap starts bubbling at about 8 minutes. It continues to bubble very lightly throughout the time the machine is on. I can't detect any other difference in operation, pro or con. No difference in early shots. I haven't pulled too many shots in a row yet to see if later shots might be improved or different in any way.

Is there anyone out there using this new type pressure cap, on an old machine or a newer one? Is the ongoing bubbling normal? Is this cap standard on later Creminas? Are there any known problems continuing to use the new cap on the old machine?

[bobcraige]

This cap was used in later Cremina machines and poses no problems in the long term. Once it reaches pressure, it should not leak. It uses an O ring seal and either a spring loaded ball or piston. If it continues to leak after the boiler is at full pressure, I would suspect that there is some contamination in the valve or the O ring is damaged. It is not a safety pressure release, but rather a check valve to prevent negative pressure on cool down and to vent air on start up.

[espressoperson]

This cap was used in later Cremina machines and poses no problems in the long term. Once it reaches pressure, it should not leak. It uses an O ring seal and either a spring loaded ball or piston. If it continues to leak after the boiler is at full pressure, I would suspect that there is some contamination in the valve or the O ring is damaged. It is not a safety pressure release, but rather a check valve to prevent negative pressure on cool down and to vent air on start up.

Thanks for the explanation. Somehow knowing what is going on makes it less worrisome. It seems that a few days of use have worked out the problems. Now it only bubbles a bit between the 8 and 10 minute marks on startup, I guess when the air gets pushed out. Presumably it does the same on cooldown but I haven't noticed.