Shut-off Valve question...

[Fiat88]

My friend who help me install my timing belt wants to know why the PO put this shut-off valve here, he thinks I should just eliminate it and put a new hose in but there's got to be a reason it's there,right?

Here's a pic:

[ventura ace]

Looks like a valve to shut off water to/from the heater core.

Alvon

[pooldoctorstl]

My guess is that the heater control valve probably doesn't close all the way because it is bad or has a linkage problem and he got tired of hot air blowing in the summer. It was easier to go to Home Depot and get a valve than it was to fix it, then he could just close the valve in the summer. I think this because right now I have the same problem as the weather is warming and I have thought about doing the same thing, but I'm going to replace the control valve.