Control system for regulating water heater operation in accordance with anticipated demand

Claim 1

A control system for selectively regulating the operation of a fluid heating tank having heating means to heat the fluid in accordance with anticipated demand for the heated fluid, comprising: first temperature sensing means for sensing the temperature of the fluid within a tank and providing a signal when said temperature is below a first predetermined level; second temperature sensing means for sensing the temperature of the fluid within the tank and providing a signal when said temperature is below a second predetermined level, said second predetermined level being higher than said first predetermined level; relay means adapted to be electrically connected to the heating means of the tank and arranged to activate the heating means when energized; first and second holding circuits for said relay means; a remote control unit including a control panel located remotely of the tank; a three-position switch means on the panel and connected in circuit with the relay means and the first and second temperature sensing means and arranged to provide selective operation of the heating means in any of three modes including: (a) a first position wherein the relay means is continuously energized under the control of the first temperature sensing means for continuous operation of the heating means to provide heated fluid at said first temperature; (b) a second position wherein the relay means is continuously energized under the control of the second temperature sensing means for continuous operation of the heating means to provide heated fluid at said second temperature; and (c) a third position permitting selective "one-time" operation of the heating means; first and second control switches on said control panel, said first control switch being arranged to actuate the first holding circuit to thereby energize the relay means when the three-position switch is in its third position to activate the heating means, the first temperature sensing means being arranged in series with the first holding circuit to break the first holding circuit upon attainment of the first temperature level in the tank, and with said second control switch being arranged to actuate the second holding circuit to thereby energize the relay means when the three-position switch is in its third position to activate the heating means, the second temperature sensing means being arranged in series with the second holding circuit to break the second holding circuit upon attainment of the second temperature level in the tank; and signal means on the control panel to provide a remote indication of the fluid temperature in the tank and the condition of activation of the heating means.