the hot water storage tank 104 which ensures that only cooler water which is stratified at the bottom of the hot water storage tank 104 is sucked back towards the lower end 122 of the heating pipes 108 to be reheated the lower end of each heating pipe 108 is closed by a drain valve 136 as illustrated in fig1 a and 2a or a cap 138 as illustrated in fig3 a closing each individual heating pipe 108 with the drain valve 136 facilitates purging from the heating pipes 108 sediment that settles to the lower end 122 as best illustrated in fig4 a and 5a in one embodiment the heating pipe 108 are placed approximately 25 mm above a corrugated highly reflective sheet 142 such as reflective aluminum foil or other reflective metal sheet having heat reflective upper and lower surfaces the reflective sheet 142 is shaped to place the heating pipes 108 at centers of focuses of corrugations in this embodiment of the solar water heating panel 102 the entire outer wall 114 of the heating pipes 108 have solar heat absorbent surfaces so that disposed in such location with respect to the reflective sheet 142 the heating pipes 108 receive and absorb the maximum direct and reflected solar radiation throughout the day this solar water heating panel 102 of heating pipes 108 over the reflective sheet 142 may be left exposed to the sun either unglazed or encased within a transparent glass cover 146 and insulated casing 148 as illustrated in fig1 a a portion of the solar water heating panel 102 extending below the casing 148 in the illustration of fig1 a depicts an alternative embodiment of the collector core 106 in which.