Sage Dual Boiler - Very low flow rate in Grouphead

[sinful galleon]

I need your help! My Sage Dual Boiler suddenly has very little flow. It takes ages to get to pressure but will eventually get to 9 bars. Even with the silicone disk it takes a really long time to get to pressure. Without a Portafilter flow is much lower than normal. Everything else seems to sound and function normally. The hot water tap and the steam work as usual. I checked if there is a problem with the flow to the group (see picture) but it is fine too. Do you habe any ideas? Solanoid Valve? Clogging inside the grouphead? What should i do next?
Thank you in advance!

[unkempt flare]

Hey, please first descale with a proper descale solution (like Calcinet)

[forest adder]

I had a similar issue and it turned out to be the solenoid. How’s your hot water spout flow look? Pump exhibiting any abnormal behavior?

[sinful galleon]

Is there a good step by step, how to descale the group head properly? I do have the old „Gastroback“ Version of the dual boiler. Descaling is unfortunately not that easy with that. But i have already descaled my boiler before.

[sinful galleon]

Hot water spout looks normal. That would have been my next guess. But I‘m not sure if it makes sense with my described „syptoms“.

[forest adder]

Hot water spout looks normal meaning the flow out of it is above 5g/s when it gets going? If so that’s what I saw, had low flow at group and it was the solenoid. I replaced the pump just to eliminate that as a suspect. For descale if you decide to go that route this is the best video I’ve found https://youtu.be/o3RScpzAan0?si=zG49ugOZR3lbU2hQ