E30 Zone

Hello again

so,i have this problem with my 325.The heating isnt working properly,i did a cleaning with waterhose through the heatingregister yesterday.The problem is that on the passenge side its blowing a bit colder than on the driverside,and its a little bit more restrictive air on passenger side.the thermostat was changed early this year,i did also flush water through the aircanals yeaterday.I was so pissed of this shit,so i just did it,so i guess there is no more shit in the heatingregister.
Has anyone here noticed that its colder on one side before?i guess it shouldnt be like this...not so cool for my girlfriend now its about -10C outside
And what about this "watervalve" inside the var,next to the register....anyone has a clue what this actually does??

Have a nice day guys

Water valve shuts off the hot water flow through the heater core when the temp knob is at or very near fully cold. At all other heat control positions, there is full flow of water through the core, temperature being controlled by blending hot and cold air.
I think I permanently damaged one once by a bit of over enthusiastic heater flushing.