Not trying to scare ya bro, but these little things are like $400 plus labor to replace them, yet the proper coolant is $25 a gallon distilled water is only .99 a gallon. Your coolant should also be blue and not green, so that's something you can check yourself as well. That diverter came from a vehicle that had a both green coolant and probably tap water as well. $5 chemical coolant flush, replaced the diverter and then his heater and A/C worked perfectly again. Everytime I see someone mention that they're dash vents are cold yet their feet are still hot or vice versa, this little guy and proper cooling system maintenance are the first things that come to mind.

Its funny i didnt have a chance to check what color coolant is but right now on my way back home 25 miles. I was driving with empty tank where i left from gas station and filled up 16 gall. hope its not related anyhow to coolant.