A self pumping solar water heating system (10, 50) comprising: a solar collector (14, 54) having upwardly sloped or vertical panels with riser tubes (37, 98), a lower collector manifold (36, 96) connected to lower ends of the riser tubes (37, 98), an upper header collector manifold (39, 104) connected to upper ends of the riser tubes (37, 98), exit tubes (40, 106) connected to the upper header collector manifold for lifting hot heat transfer fluid, a first reservoir connected to the exit tubes (40, 106) for receiving the hot heat transfer fluid from the exit tubes, a first pipe (44, 56, 112) connected to the first reservoir, a heat exchanger (18, 58) connected to the first pipe (44, 56, 112) for receiving hot heat transfer fluid from the first reservoir, a hot water storage tank (12, 52) connected to the heat exchanger (18, 58), a second pipe (16, 32, 92) connected to the heat exchanger (18, 58) for returning the cooled heat transfer fluid to a second reservoir, said second reservoir being positioned below the first reservoir and connected to the second pipe (16, 32, 92), a return tube (34, 94) connected to the second reservoir and to the lower collector manifold (36, 98), and a vapor pipe (42, 114) connected from an upper part of the first reservoir for releasing steam from the first reservoir to condensate in the second reservoir, the system being characterized in that it further comprises a third reservoir connected to a top of the second reservoir and a float valve connected to a bottom of the third reservoir for opening to permit vapor and heat transfer fluid into the third reservoir and to permit the heat transfer fluid return from the third reservoir to the second reservoir. a solar collector (14, 54) having upwardly sloped or vertical panels with riser tubes (37, 98), a lower collector manifold (36, 96) connected to lower ends of the riser tubes (37, 98), an upper header collector manifold (39, 104) connected to upper ends of the riser tubes (37, 98), exit tubes (40, 106) connected to the upper header collector manifold for lifting hot heat transfer fluid, a first reservoir connected to the exit tubes (40, 106) for receiving the hot heat transfer fluid from the exit tubes, a first pipe (44, 56, 112) connected to the first reservoir, a heat exchanger (18, 58) connected to the first pipe (44, 56, 112) for receiving hot heat transfer fluid from the first reservoir, a hot water storage tank (12, 52) connected to the heat exchanger (18, 58), a second pipe (16, 32, 92) connected to the heat exchanger (18, 58) for returning the cooled heat transfer fluid to a second reservoir, said second reservoir being positioned below the first reservoir and connected to the second pipe (16, 32, 92), a return tube (34, 94) connected to the second reservoir and to the lower collector manifold (36, 98), and a vapor pipe (42, 114) connected from an upper part of the first reservoir for releasing steam from the first reservoir to condensate in the second reservoir, the system being characterized in that it further comprises a third reservoir connected to a top of the second reservoir and a float valve connected to a bottom of the third reservoir for opening to permit vapor and heat transfer fluid into the third reservoir and to permit the heat transfer fluid return from the third reservoir to the second reservoir.