Hi. i have a secondary pump that is dedicated solar heating
it pumps to black hoses on roof of garage about ten foot head height
anyway it loses its prime after about 12 hours of being turned off
this means i can't leave it on automatic as there is no protection to turn off pump if no flow
there are no water leaks when operating and after primed and running for half an hour there are no bubbles in the return line
anybody have any tips to try and find where it is drawing in air when turned off.