Greetings fellow Reddit users,
I would like to share my experience with the Expert Machine – perhaps some of you will find it useful:
After more than seven years of flawless operation (used daily) the machine started making hissing and gurgling noises when it’s turned on and idling. A little steam coming out of the loading bay when it’s open, too – but that’s pretty much it, no coffee going straight into tray, etc.
I’ve seen a few archived posts about same issue – so I decided to do a little DIY project to find out the cause. I actually thought the culprit was the small rubber O-ring put between the thermoblock and brewing unit. I bought the OEM part (Krups p/n MS-623318, if anyone is interested) and replaced it, following the factory service manual.
After putting everything back together and testing, I unfortunately have to admit that the sound and steam are still there, so the reason is obviously not the old O-ring: it was already a bit square-ish after years of use, but it wasn’t leaking.
Now I think Expert machine users notice this phenomenon because its (and U’s, I believe) default brewing unit position is open, not closed like in other models – so any steam coming out of the thermoblock can be heard and seen. Using logic, that means there must be some sort of cutoff or one-way valve of some kind before the thermoblock that started passing a bit of water when idling.
I will look closer into it, maybe try changing the water pump and see what happens. Funny thing is, if I open the loading bay of my old Pixie machine when it’s on, it also has steam coming out of the brewing unit )
Thanks for reading, any thoughts from fellow Expert owners is much appreciated!
by Tomcat-R