Siemens EQ 5 macchiato water under machine

Hello. I have Siemens EQ5 macchiato from second hand. Get it mostly for free smile.gif It was ok for few cups but now i notice that water is going under machine from back where power cord is. And after that several problems start to occur.

First problem: When machine is ON, it asks me to pull the frother and start filling the system with water, then asks me to push it back. After pumping nothing is comming from nozzles where coffee is supose to come. But i hear that water is going into drip drain and it's doing this loop forever until it rech the nozzles somehow. Sometimes it reach the nozzles and after that machine works "fine".

Second problem: When machine is ready to make coffee (after first problem) i choose program, coffee is grinding and all seems ok, but when coffee starts to comming from nozzles i see message "Check water tank" and high pressured steam is comming out from brew unit. Sometimes i managed to make coffee without problems on this step.

After many hour of research i tried to descale it with vinegar and citric acid, but it doesn't help. Then i disassembled the machine and check all pipelines to find where is water leaking, and all seems to be fine. Then i thought maybe there is air blocakage and i tried to pump the air with syringe, and this also doesn't help. I also check and clean this little white turbine thing that measures water, no result.

Also, when machine is off, it seems that water is still leaking under machine. Do i need to replace pump?

I also checked a valve, forgot the name... My machine don't have ceramic valve, but have two plastic or acrylic pipes, all seems to be fine.

Thanks for help in advance.

For me, the first measure is to replace the pump, which could solve both problems, because if water is drawn from the water tank when it is switched off, a spring is usually broken inside the pump.
Descaling is essential after pump replacement, but never with vinegar or citric acid, but with amidosulfone-based descaler, because this dissolves lime and does not dissolve lime lumps that can clog the machine.

Thanks for the reply and usefull tips! I will buy a new pump and then tell if problem was fixed. Is there any chance to fix the pump? And also what can cause a water leak under machine?

Little update here. I disassembled the pump and assemble it again and my problem solved. All parts look like they brand new. But the problem with water leak under machine is still there. What can cause it? All water supply pipes is fine. Can it be a brewing unit?

And "Check water tank" still here... I think it's because of water leak from somewhere, but not through pipes... When coffee starts to brew process interrupts, coffee powder is dry and "Check water tank" appears