Water heating system

Abstract

A water heating system including a water container having a cold water inlet that connects to a water supply, a hot water outlet, a water heater outlet and a water heater inlet; an instantaneous water heater mounted to the water container and having a tank supply inlet connected to the water heater outlet, a tank supply outlet connected to the water heater inlet, a burner, and a heat exchanger located adjacent the burner between the tank supply inlet and the tank supply outlet; a pump connected between the water container and the instantaneous water heater that moves water between the water container and the instantaneous water heater; and a controller that operates the pump and the burner.

1 . A water heating system comprising:
 a water container having a cold water inlet that connects to a water supply, a hot water outlet, a water heater outlet and a water heater inlet;   an instantaneous water heater mounted to the water container and having a tank supply inlet connected to the water heater outlet, a tank supply outlet connected to the water heater inlet, a burner, and a heat exchanger located adjacent the burner between the tank supply inlet and the tank supply outlet;   a pump connected between the water container and the instantaneous water heater that moves water between the water container and the instantaneous water heater, and   a controller that operates the pump and the burner.   
   
   
       2 . The water heating system according to  claim 1 , wherein the instantaneous water heater is the only source of heat supplied to water in the water container. 
   
   
       3 . The water heating system according to  claim 1 , wherein the instantaneous water heater is mounted to a side portion of the water container. 
   
   
       4 . The water heating system according to  claim 1 , wherein the water container comprises a substantially cylindrical water tank, insulation substantially surrounding the tank and a jacket substantially surrounding the insulation. 
   
   
       5 . The water heater system according to  claim 4 , further comprising a mounting bracket at least partially shaped on one side to substantially approximate the shape of at least a portion of the jacket and at least partially shaped on an opposed side to substantially approximate the shape of at least a portion of one side of the instantaneous water heater. 
   
   
       6 . The water heater system according to  claim 1 , wherein the cold water inlet is located at an upper portion of the water container and the water container further comprises a dip tube connected to the cold water inlet that extends toward a lower portion of the water container. 
   
   
       7 . The water heater system according to  claim 6 , wherein the burner supply outlet is located on a side portion of the water container at a height from the bottom of the water container that is approximately the height at which a distal end of the dip tube ends. 
   
   
       8 . The water heater system according to  claim 1 , wherein the water heater outlet is located in a lower portion of the water container. 
   
   
       9 . The water heater system according to  claim 1 , wherein the water heater inlet is located in an upper portion of the water container. 
   
   
       10 . The water heater system according to  claim 1 , wherein the instantaneous water heater further comprises a flammable vapor sensor connected to the controller and proximate a location where combustion air enters the burner. 
   
   
       11 . The water heater system according to  claim 1 , wherein the instantaneous water heater further comprises a CO sensor connected to the controller and proximate a location where flue gases exit the burner. 
   
   
       12 . The water heater system according to  claim 1 , wherein the water container further comprises a thermistor connected to the controller and positioned to sense temperature of water in the tank. 
   
   
       13 . The water heating system according to  claim 12 , wherein the thermistor is positioned at a lower portion of the water container. 
   
   
       14 . The water heater system according to  claim 12 , wherein the thermistor is located proximate to the water heater outlet. 
   
   
       15 . The water heater system according to  claim 1 , further comprising a thermistor connected to the controller and positioned between the water heater inlet and the heat exchanger. 
   
   
       16 . The water heater system according to  claim 1 , wherein the burner is a burner whose heat output is adjusted by the controller in response to temperature of water entering the instantaneous water heater. 
   
   
       17 . The water heater system according to  claim 16 , wherein the burner produces about 30,000- about 100,000 BTU/hr. 
   
   
       18 . The water heater system according to  claim 16 , wherein the burner produces about 44,000- about 100,000 BTU/hr. 
   
   
       19 . The water heating system according to  claim 1 , wherein the water heater inlet is located at an upper portion of the water container and shaped to direct heated water substantially horizontally circularly within the water container. 
   
   
       20 . A method of heating water with the system according to  claim 1 , comprising:
 causing hot water to flow outwardly of the water container through the hot water outlet;   sensing temperature of water in the water container;   engaging the pump; and   igniting the burner.   
   
   
       21 . The method of heating water according to  claim 20 , further comprising, prior to engaging the pump:
 sensing presence of flammable vapors with a flammable vapors sensor and signaling the controller if a sensed concentration of flammable vapors exceeds a selected flammable vapors concentration; and   engaging a combustion air fan proximate the burner if sensed concentration of flammable vapors is below the selected flammable vapors concentration for a selected time period and signaling the controller if the sensed concentration of flammable vapors exceeds the selected flammable vapors concentration.   
   
   
       22 . The method of heating water according to  claim 20 , further comprising adjusting the burner to provide varying amounts of heat to the heat exchanger in response to temperature of water exiting the water container. 
   
   
       23 . A method of substantially maintaining a selected temperature of water in the water container of the system according to  claim 1 , comprising:
 sensing temperature of the water in the water container;   comparing a sensed water temperature to a selected water set temperature;   engaging the pump if the sensed water temperature is less than the selected water set temperature; and   igniting the burner.   
   
   
       24 . The method of heating water according to  claim 23 , further comprising, prior to igniting the burner:
 sensing flow of water moving from the water container to the instantaneous water heater.   
   
   
       25 . The method of heating water according to  claim 23 , further comprising, prior to engaging the pump:
 sensing presence of flammable vapors with a flammable vapors sensor and signaling the controller if a sensed concentration of flammable vapors exceeds a selected flammable vapors concentration; and   engaging a combustion air fan proximate the burner if the sensed concentration of flammable vapors is below the selected flammable vapors concentration for a selected time period and signaling the controller if the sensed concentration of flammable vapors exceeds the selected flammable vapors concentration.   
   
   
       26 . The method of heating water according to  claim 23 , further comprising adjusting the burner to provide varying amounts of heat to the heat exchanger in response to temperature of the water exiting the water container. 
   
   
       27 . The method of heating water according to  claim 19 , further comprising, prior to igniting the burner:
 sensing flow of water moving from the water container to the instantaneous water heater.   
   
   
       28 . A method of preventing water in the instantaneous water heater according to  claim 1  from freezing comprising:
 sensing temperature of water proximate to or in the heat exchanger;   comparing the sensed water temperature to a first selected water temperature;   comparing the sensed water temperature to a second selected water temperature if the sensed water temperature is less than the first selected water temperature:
 1) engaging the pump if the sensed water temperature is greater than the second selected water temperature; 
 2) sensing temperature of water in the water container; 
 3) comparing the water container sensed temperature to a third selected water temperature; and 
 4) disengaging the pump if the water container sensed temperature is greater than the third selected water temperature; or 
 1) engaging the pump if the sensed water temperature is less than the second selected water temperature; 
 2) sensing temperature of water proximate to or in the heat exchanger; 
 3) comparing sensed heat exchanger water temperature to the third selected water temperature; and 
 4) disengaging the pump in the sensed heat exchanger water temperature is greater than the third selected water temperature. 
   
   
   
       29 . A water heater system comprising:
 a burner unit adapted to heat water;   a water container associated with the burner unit and having a cold water inlet and a hot water outlet; and   a controller that operates the burner to maintain the temperature of water in the water container above about 100° F. and substantially within a range of about 10° F. when at least about 2.5 gpm of heated water is removed substantially continuously from the water container for at least about 15 minutes.   
   
   
       30 . The system according to  claim 29 , wherein the temperature is about 100° F. to about 110° F. 
   
   
       31 . The system according to  claim 29 , wherein the temperature is about 130° F. to about 140° F. 
   
   
       32 . The system according to  claim 29 , when the range is about 5° F. 
   
   
       33 . The system according to  claim 29 , wherein the controller maintains the temperature for at least about 30 minutes. 
   
   
       34 . The system according to  claim 29 , wherein the controller maintains the temperature for at least about 60 minutes. 
   
   
       35 . The system according to  claim 29 , wherein at least about 5.0 gpm of heated water is removed. 
   
   
       36 . The system according to  claim 29 , wherein the temperature of heated water exiting the water container does not increase by more than about 10° F. for a selected time. 
   
   
       37 . The system according to  claim 36 , wherein the temperature of heated water exiting the water container does not increase by more than about 2° F. 
   
   
       38 . The system according to  claim 29 , further comprising a pump that introduces heated water into the water container. 
   
   
       39 . The system according to  claim 29 , wherein the burner unit is mounted on a side portion of the water container.