A solar collector (100), comprising: (a) a plurality of thermosiphon tubes (202) in which water flows, each tube (202) having a top opening and a bottom opening; (b) a top manifold (102) having a water inlet (106) and water outlet (108) and disposed at the top opening of the tubes (202), providing both a water feed into at least one of the plurality of tubes (202) and a water exit from the rest of the tubes (202); and (c) a bottom basin (104) connecting the bottom openings of the tubes (202). In some embodiments the plurality of tubes (202) are divided into at least one inlet tube (202) and the rest as outlet tubes (202) by a stopper (302) disposed in the top manifold (102).