europa The vacuum breaker vents to the drip tray, so it’s the expansion valve or as @MediumRoastSteam says, could be the safety valve. It’s difficult to tell, but in the first video, there appears to be bubbles emanating from the safety valve? Does this always happen? The cameras moving around a lot so difficult to see.
From your description there appears to be multiple errors
- Leaking Safety valve?
- Funny solenoid action
- Pump activation without steam boiler filling?
- Steam is OK but splutters?
- leaking connector?
- pump runs on?
- is there a level probe fault?
So many problems, that might or might not be happening, I am having trouble just zoning in on things in a deluge of “possible” information. You need to compartmentalise this and work through a series of logical steps to figure this out. Let me give you some examples, of my thought processes….
Is the service boiler over filling - open steam wand and run pump against a blind filter, or next time it autofills open steam wand. (It is tricky with the hot water, because it always takes that from the brew boiler). or remove a fitting and look (cold boiler of course)?
Isolate the tube from the safety valve…is the water actually coming from there…or the vacuum breaker
Is that clunking a solenoid, or the safety valve popping open and closed (if it’s the safety valve) then the only thing wrong with the machine might be a faulty safety valve. It’s why I asked if you could feel (with a wooden dowel) any solenoids clicking). Although it doesn’t explain why the pump runs on…perhaps another fault with the level probe wire.