Follow-up:
The location of your up-and-over-and-down hose in the pic on p 154 of this thread is correct. Lots of nice pics of different pretty ways to do it are here:
https://www.google.com/search?q=vort...h2CLUQ_AUIBygC
You need to do it, because you do NOT want to be circulating coolant through your heater in the summer. I put a valve on mine so I could shut it off, because there is minimum amount of heat you get from the heater even when it is shut off. And when it gets hot here, any amount of heat is too much.