M380 Hurricane Heater

[davidbrady]

Chuck, do you have an old SHURflo water pump lying around? Those pumps are self-priming and would work.

I'm confused. The March pump isn't self priming, but if you're getting fluid flow thru Loop 1 then the pump's primed, and if the pump is primed then with the head it's capable of it should be able to push fluid thru Loop 2. Now I'm leaning more towards a mechanical obstruction.

Maybe you can disconnect Loop 2 and drain it of any remaining fluid and hook up a supply of regulated air to see if you can very, very, gently blow thru it, rather than deal with the messy fluid. Too much air and you can easily damage heat registers or split apart connectors. (with safety goggles, I don't want a dislodged projectile to hit you on the head)!