the lower discharge end 52 are included at the extremities of this first heat exchanger 48 the upper feed end 50 extending upwardly and exteriorly through the confining wall 54 of the storage tank 42 while the lower discharge end 52 extends to the bottom concave wall 56 a solar collector unit 58 is located outdoors and at an elevation above that of any portion of the first heat exchanger 48 including the upper feed end 50 the solar collector unit 58 is provided with a cold circulation fluid inlet 60 and a hot circulation fluid outlet 62 a drain back solar water heating tank 64 physically separated from the storage tank 42 by a concave wall 56 is located at an elevation lower than that of the first heat exchanger 48 and includes a drainpipe 66 in its 39 lower portion the lower discharge end 52 of the first heat exchanger 48 extends to the concave wall 56 of the storage tank 42 ending at the drain back tank 64 recirculation fluid travels toward the lower discharge end 52 of the first heat exchanger 48 exiting into the drain back tank 64 directly above a baffle plate 70 the baffle plate 70 having randomly positioned apertures 71.