Patent ID: 8109264

Claim:
A solar water heating system comprising a first solar collector outside a building, the collector having a solar energy absorbing member; a heated water storage tank inside the building; a water conduit extending from the tank, outside the building, through the collector, inside the building and back to the tank; water in the conduit; said conduit including a first conduit portion in heat-flow engagement with said absorbing member and a second conduit portion, said first and second portions outside the building and exposed to freezing temperatures; a circulation pump in said water conduit, wherein the pump normally flows water from the tank through the conduit, past the energy absorber for heating by solar energy and back to the tank; a flow detector for said water conduit; a resistance-heating wire located in said second conduit portion in heat-flow communication with an ice blockage in said second conduit portion; and a control member for flowing electricity through the resistance wire in response to a reduced flow signal from the flow detector; wherein when water in the second portion of the water conduit freezes to form an ice blockage which reduces the flow of water through the water conduit the resistance wire is actuated to melt the ice blockage and reestablish flow through the water conduit.