System and method for water heater twinning

Abstract

A water heater system includes a first water heater including a first controller configured to transmit and receive a token; and a second water heater including a second controller configured to transmit and receive the token. The first water heater is plumbed to the second water heater in a twinned configuration, and the first controller is in communication with the second controller. The first controller is configured to control the first water heater to perform a first heating cycle while in possession of the token, and then transmit the token to the second controller, and the second controller is configured to control the second water heater to perform a second heating cycle while in possession of the token, and then transmit the token to the first controller.

1 . A water heater system comprising:
 a first water heater including a first controller configured to transmit and receive a token; and   a second water heater including a second controller configured to transmit and receive the token;   the first water heater being plumbed to the second water heater in a twinned configuration, and the first controller being in communication with the second controller,   the first controller being configured to control the first water heater to perform a first heating cycle while in possession of the token, and then transmit the token to the second controller, and   the second controller being configured to control the second water heater to perform a second heating cycle while in possession of the token, and then transmit the token to the first controller.   
     
     
         2 . The water heater system of  claim 1 , wherein the possession of the token is required for authorization to perform a heating cycle in order to ensure non-simultaneously operation of the first water heater and the second water heater. 
     
     
         3 . The water heater system of  claim 1 , further comprising:
 a first temperature sensor for monitoring a first temperature in the first water heater, and   a second temperature sensor for monitoring a second temperature in the second water heater,   the first controller and the second controller being further configured to control the possession of the token based on the first temperature and the second temperature.   
     
     
         4 . The water heater system of  claim 3 , wherein the first controller and the second controller are further configured to determine whether the twinned configuration is a series plumbing configuration or a parallel plumbing configuration of the first water heater and the second water heater based on a change of the first temperature and the second temperature, or a rate of change of the first temperature and the second temperature, in response to a draw of water from the water heater system. 
     
     
         5 . The water heater system of  claim 3 , wherein the first controller and the second controller are further configured to determine whether the twinned configuration is a series plumbing configuration or a parallel plumbing configuration of the first water heater and the second water heater based on the first temperature and the second temperature. 
     
     
         6 . The water heater system of  claim 4 , wherein the first controller and the second controller are further configured to determine the series plumbing configuration by:
 comparing the first temperature rate of change and the second temperature rate of change to a predetermined draw rate temperature rate of change;   determining that the first water heater and the second water heater are in the series plumbing configuration when the comparison indicates that only one of the first temperature rate of change or the second temperature rate of change is equal to or greater than the draw rate temperature rate of change.   
     
     
         7 . The water heater system of  claim 4 , wherein the first controller and the second controller are further configured to determine the parallel plumbing configuration by:
 comparing the first temperature rate of change and the second temperature rate of change to a predetermined draw rate temperature rate of change;   determining that the first water heater and the second water heater are in the parallel plumbing configuration when the comparison indicates that both of the first temperature rate of change and the second temperature rate of change are equal to or greater than the draw rate temperature rate of change.   
     
     
         8 . The water heater system of  claim 4 , wherein the first controller and the second controller are further configured to:
 control the possession of the token in a first sequence when the series plumbing configuration is determined, and   control the possession of the token in a second sequence when the parallel plumbing configuration is determined.   
     
     
         9 . The water heater system of  claim 8 ,
 wherein at least one of the first controller and the second controller is further configured to:
 for the series plumbing configuration, control the possession of the token in the first sequence by:
 determining which of the first water heater and the second water heater is a down-stream water heater, and which of the first water heater and the second water heater is an up-stream water heater, and 
 passing the token between the first controller of the first water heater and the second controller of the second water heater to give preference to the up-stream water heater; and 
 
 for the parallel plumbing configuration, control the possession of the token in the second sequence by:
 passing the token between the first controller of the first water heater and the second controller of the second water heater to give equal preference to both the first water heater and the second water heater, and 
 
 wherein the possession of the token provides permission to perform a heating cycle, and non-possession of the token prohibits performing the heating cycle to ensure non-simultaneous operation of the first water heater and the second water heater. 
   
     
     
         10 . The water heater system of  claim 1 , the first water heater being a leader water heater and the first controller being a leader controller, and the second water heater being a follower water heater and the second controller being a follower controller,
 wherein the leader controller of the leader water heater is configured to control distribution of the token to the follower controller of the follower water heater.   
     
     
         11 . The twined water heater system of  claim 10 , the leader controller being further configured to lead control of the token in response to the leader controller being set to a setpoint temperature. 
     
     
         12 . The water heater system of  claim 10 , the follower controller being configured to permit control of the token by the leader controller in response to the follower controller being set to a predetermined mode. 
     
     
         13 . The water heater system of  claim 10 , wherein the possession of the token is required for authorization to perform a heating cycle in order to ensure non-simultaneously operation of the leader water heater and the follower water heater. 
     
     
         14 . The water heater system of  claim 10 , further comprising:
 a leader temperature sensor for monitoring leader temperature in the leader water heater, and   a follower temperature sensor for monitoring follower temperature in the follower water heater,   wherein the leader controller is further configured to control the possession of the token based on the leader temperature detected by the leader temperature sensor and the follower temperature detected by the follower temperature sensor.   
     
     
         15 . The water heater system of  claim 9 , the down-stream water heater being configured to supply heated water to an end user. 
     
     
         16 . The water heater system of  claim 9 , the up-stream water heater being configured to receive water to be heated from a water supply. 
     
     
         17 . The water heater system of  claim 1 , wherein the first water heater and the second water heater share a common electrical circuit. 
     
     
         18 . The water heater system of  claim 1 , wherein the first water heater and the second water heater are configured to share portions of the token. 
     
     
         19 . The water heater system of  claim 18 , wherein the portions of the token determine an authorized power capacity of a heating element of the first water heater or the second water heater. 
     
     
         20 . A method for controlling the water heater system of  claim 1  including the first water heater having the first controller and the second water heater having the second controller, where the first water heater is plumbed to the second water heater in a twinned configuration and the first controller of the first water heater is in communication with the second controller of the second water heater, the method comprising:
 controlling, by the first controller, the first water heater to perform the first heating cycle while in possession of the token; 
 transmitting, by the first controller, the token to the second controller; 
 controlling, by the second controller, the second water heater to perform the second heating cycle while in possession of the token; and 
 transmitting, by the second controller, the token to the first controller. 
 
     
     
         21 . The method of  claim 20 , further comprising:
 determining possession of the token for authorization to perform a heating cycle to ensure non-simultaneous operation of the first water heater and the second water heater.   
     
     
         22 . The method of  claim 20 , further comprising:
 monitoring, by a first temperature sensor, a first temperature in the first water heater;   monitoring, by a second temperature sensor, a second temperature in the second water heater;   controlling, by the first controller and the second controller, the possession of the token based on the first temperature and the second temperature.   
     
     
         23 . The method of  claim 22 , further comprising:
 determining, by the first controller and the second controller, a series plumbing configuration or a parallel plumbing configuration between the first water heater and the second water heater based on a change of the first temperature and the second temperature, or a rate of change of the first temperature and the second temperature, in response to a draw of water from the water heater system.   
     
     
         24 . The method of  claim 22 , further comprising:
 determining, by the first controller and the second controller, a series plumbing configuration or a parallel plumbing configuration between the first water heater and the second water heater based on the first temperature and the second temperature.   
     
     
         25 - 38 . (canceled)