Patent ID: 8498527

Claim:
A water heating control and storage system, comprising: an insulated tank for containing water to be heated; at least two heating elements including an upper heating element and a lower heating element positioned within said tank; wherein said upper heating element further comprises an upper thermostat and said lower heating element comprises a lower thermostat; and an operation control device configured to (i) operate the system in multiple operating modes comprising a first operating mode where both of said upper heating element and said lower heating element are enabled, a second operating mode where both of said upper heating element and said lower heating element are disabled, and a third operating mode where one of said upper heating element and said lower heating element is enabled and the other of said upper heating element and said lower heating element is disabled to independently heat upper and lower portions of said tank, and (ii) receive and process a demand response signal and in response to said signal selectively operate said system in one of said operating modes or allow said upper thermostat and said lower thermostat to assume control of whether said upper heating element and said lower heating element are respectively enabled or disabled.