JURA C5 Error message

I have a JURA C5 from my parents-in-law, but unfortunately the machine is not very well maintained either.
When I turn on the machine, the following people flash: Water tank empty, appliance calcified, and the bar from the steam tap. When I open the steam tap the pump runs and there is very little water in the collection tray. I cleaned the drainage valve and installed a new seal, I had done the brewing group about 2 years ago. What I also noticed was that some limestone was deposited in one of the tubes. The float in the water tank is free and is also rising, now I hope that you can give me a tip.

When you turn the steam tap, water must come out at the front of the hot water nozzle.
check the water path from the F-distributor to the hot water nozzle. You can also unscrew the connector on the hot water nozzle. Not that
that's closed.

There must be something. Therefore, the water goes away via the drainage valve. Outlet valve Can also

be checked at the same time.
If everything is free and running I would descale the water.

Thanks,

it fails to be due to the siphon valve. I have today times to you lines agreed, the connection of the supply line to the steam valve was completely too with lime. I already have the connection clean but the valve is not yet free. The steam valve is now lying in citric acid, let's see if it is free again.

If you have an amidosulfonic acid base, it would be more effective. For example Eilfix, Durgol or similar. Citric acid only dissolves. The above is much better for severe decalcification.

No, unfortunately I do not, what I have is an aggressive urinary stone removal.
The valve is now inside for soaking, if that doesn't work I will probably order a new valve.

The urine stone remover helped, but I can only install the valve again tomorrow.