I don't believe it would make any difference what connects top or bottom. Aesthetically it looks better top to top IMHO. If you put a shut off valve in line I think it's best to put it on the "push" side of the pump to keep the pressure off of the heater core when not in use.


Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.