Patent ID: 8567689

Claim:
A method of operating a hot water supply system comprising the steps of: (1) providing a hot water supply system including a water storage tank, and a pump for delivering water from said water storage tank to a heat exchanger; (2) operating said pump under normal conditions to draw a cool water from said water storage tank, and pass it through pipes communicating said water storage tank to said pump and to said heat exchanger, and monitoring an amount of cool water in said water storage tank relative to an amount of hotter water, and normally stopping operation of said pump passing cool water to said heat exchanger when the amount of hotter water relative to cool water reaches a predetermined amount; and (3) operating said system in a sanitation mode at which hotter temperature water is brought through said pipes and said pump, and in said sanitation mode, said pump not stopping operation when the amount of hotter water relative to cool water exceeds the predetermined amount, but continuing to pass water from said water storage tank through said heat exchanger such that a higher temperature water is brought through said pipes and said pump.