Quick blinking doesnt stop after NTC sensor replacement

Hi,

I have a problem with Citiz&Milk C120, I guess it's similar to the subject. The machine is in descaling mode permanently, can't quit no matter what. After disassembly and checking with the repair manual, hot thermostat and quick blinking indicates faulty NTC sensor and requires it's replacement.

NTC sensor replacement didn't help and the machine goes into fault mode (quick blinking) after some heating of thermostat.

Has anyone faced this problem and maybe knows where to look for the problem?