I am putting together a solar water heating system, small with one 4 x 8 ft homemade collector and a 35-gal. storage tank with a 10-gal. drainback tank. I would prefer to use a pump that is DC and since this is a PV-powered home, has reasonable electrical usage. The pump needs to have no check valve [or a removable one I can toss], since it gets cold here, very cold, and drainback is essential. The head I anticipate being in the neighborhood of ten feet, perhaps slightly more, though I will not have an exact number til this weekend when I can better measure.

Any recommendations? I have found the usual Taco and Grunfos hot water circulating pumps online. All AC pumps. The 12 v. pumps I've read about have very small head capabilities.