I bought a Francis Francis X5 on FB Marketplace. It works alright, but when it heats up it makes a very loud whistle sound and spews water from the group head. After this the bottom orange light is off and it is then ready to make an espresso.
Thinking it was full of limescale I mixed some citric acid powder with water and ran it through the machine. I did an entire water reservoir. After that the machine stopped working completely for a while. No water would come from the group head when the button was pressed. The steam wand stayed working. After a few hours (probably when the machine had cooled down), the espresso button worked again, but there was a very strong smell of burnt plastic.
Now a day later the machine works as when I bought it, ie: it makes an espresso but it whistles and spews water. Besides that it seems to work alright.
I tried to unscrew the group head screen screw from underneath but it is stuck and I think by now I have damaged the screw. Are there any easy ways to undo this screw?
Thanks for any advice you all may have!