So, basically, water_in and water_out don't work as intended, while setting T_Sensor makes AI Suite to react - Fans work properly, dependending on sensor, connected to T_Sensor.
Water_IN/OUT though, make the fans stuck at ~minimum bar, regardless of temperature sensor is reading.
Fans are in 100% working condition - they work perfectly, as well as sensor I'm using (it does reports correct info) and sensor connectors on the motherboard - all of them DO report correct info.
So what should I do to make WATER_IN and WATER_OUT fully workable?
P.S. As for me - I would say, it's suite flaw. AS always.....