Preferred position of circulator?

[TSN79]

In a closed water heating system with a heat exchanger as the primary heat source (district heating), should the circulator ideally be installed before or after the heat exchanger? Is one or the other better for the exchanger itself?

 

[Paul Colby]

If the hot water is drawn on demand then after the heat exchanger would put more thermal cycles on the pump? If this is the case it might suggest placing it before the heat exchanger. Just a thought.

 

[Vedward]

The circulator needs to be installed with the expansion tank connection on the suction.