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EP-4469731-B1 - FREEZE PROTECTION VALVES, SYSTEMS, AND METHODS

EP4469731B1EP 4469731 B1EP4469731 B1EP 4469731B1EP-4469731-B1

Inventors

  • SEMBA, YOSHIKI
  • BROWN, JACOB H.
  • Hayden, Christopher M.
  • TOMASCO, Sarah N.
  • SATYANARAYANA, HARSHA
  • MANAY, ATILHAN
  • BINDBEUTEL, Derek
  • PARBHOO, Rajan

Dates

Publication Date
20260513
Application Date
20230124

Claims (15)

  1. A freeze protection system (108) comprising: a first valve (110) configured to be coupled with an inlet of a water heater (102); a second valve (112) configured to be coupled with an outlet of the water heater (102); and characterized in further comprising a valve actuator (120) configured to automatically actuate the first valve (110) and the second valve (112) to permit water to drain from the water heater (102) when, 1, electric power is lost to the water heater (102), and, 2, a temperature of a fluid in or around the water heater (102) is less than or equal to a predetermined low temperature threshold.
  2. The freeze protection system of claim 1, wherein the valve actuator (120) comprises a solenoid switch (606) configured to transition between an open state and a closed state.
  3. The freeze protection system of claim 2, wherein the valve actuator (120) further comprises a temperature switch (604) configured to close when the temperature of the fluid is less than or equal to the low temperature threshold.
  4. The freeze protection system of claim 3, wherein the temperature switch (604) comprises a bimetal component configured to cause the temperature switch (604) to close when the temperature of the fluid is less than or equal to the low temperature threshold.
  5. The freeze protection system of claim 3, wherein the temperature switch (604) comprises a pneumatic actuator having a gas that is configured to contract when the temperature of the fluid is less than or equal to the low temperature threshold, thereby causing the temperature switch (604) to close, or wherein the temperature switch (604) comprises a hydraulic actuator having a liquid that is configured to expand when the temperature of the fluid is less than or equal to the low temperature threshold, thereby causing the temperature switch (604) to close.
  6. The freeze protection system of claim 3, further comprising an energy storage device (602), wherein, when a power switch is closed and the temperature switch (604) is closed, the energy storage device (602) is configured to discharge and cause the first valve (110) and the second valve (112) to actuate, thereby permitting the water to drain from the water heater (102).
  7. The freeze protection system of claim 1, wherein the valve actuator (120) comprises a solenoid valve (744) configured to transition from an open state to a closed state when the electric power is lost to the water heater (102), such that when the solenoid valve (744) is in the open state, the solenoid valve (744) permits water to flow into the water heater (102), and when the solenoid valve (744) is in the closed state, the solenoid valve (102) prevents water from flowing into the water heater (102).
  8. The freeze protection system of claim 7, wherein the valve actuator (120) further comprises a temperature actuator configured to permit the solenoid valve (744) to transition to the closed state when the temperature of the fluid is less than or equal to the low temperature threshold, and prevent the solenoid valve (744) from transitioning to the closed state when the temperature of the fluid is greater than or equal to the low temperature threshold, optionally wherein the temperature actuator comprises an elongated portion (848) configured to extend into a pathway of the solenoid valve (744) when the temperature of the fluid is greater than the low temperature threshold, thereby preventing the solenoid valve (744) from transitioning to the closed state, and retract out of the pathway of the solenoid valve (744) when the temperature of the fluid is less than or equal to the low temperature threshold, thereby permitting the solenoid valve (744) to transition to the closed state.
  9. The freeze protection system of claim 8, wherein the temperature actuator comprises: a pneumatic actuator (740) having a gas that is configured to contract when the temperature of the fluid is less than or equal to the low temperature threshold, thereby causing the temperature actuator to retract out of the pathway of the solenoid valve (744), or a hydraulic actuator (750) having a liquid that is configured to expand when the temperature of the fluid is less than or equal to the low temperature threshold, thereby causing the temperature actuator to retract out of the pathway of the solenoid valve (744).
  10. The freeze protection system of claim 1, further comprising an on-delay timer (428) configured to delay re-supply of electric power to the water heater (402) for a period after restoration of electric power.
  11. A water heater comprising: a tank having a water inlet and a water outlet; and the freeze protection system (108) of any one of claims 1 to 10, wherein the first valve (110) is connected to and in fluid communication with the water inlet, and the second valve (112) is connected to and in fluid communication with the water outlet.
  12. The water heater of claim 11, comprising a valve assembly (1000) which comprises: a first fluid pathway (1062) configured to permit water to flow from a water source and through the water heater (102); a second fluid pathway (1064) configured to permit the water to drain from the water heater (102); and a plug (1060) configured to transition between a first position and a second position, the plug (1060) being configured to open the first fluid pathway (1062) and close the second fluid pathway (1064) when in the first position, and close the first fluid pathway (1062) and open the second fluid pathway (1064) when in the second position, wherein the valve actuator (120) is configured to automatically actuate the plug (1060) from the first position and to the second position when, 1, electric power is lost to the water heater (102), and, 2, the temperature of the fluid in or around the water heater (102) is less than or equal to the predetermined low temperature threshold.
  13. The water heater of claim 12, wherein the valve actuator (120) comprises: a solenoid valve (744) configured to transition from a first state to a second state when power is lost to the water heater, such that when the solenoid valve (744) is in the first state, the solenoid valve (744) is configured to cause the plug (1060) to be in the first position, and when the solenoid valve (744) is in the second state, the solenoid valve (744) is configured cause the plug (1060) to be in the second position; and a temperature actuator configured to permit the solenoid valve (744) to transition to the second state when the temperature of the fluid is less than or equal to the low temperature threshold, and prevent the solenoid valve (744) from transitioning to the second state when the temperature of the fluid is greater than or equal to the low temperature threshold.
  14. A method of controlling a freeze protection system, the method comprising: actuating a first valve (110) and a second valve (112), wherein the first valve (110) is in fluid communication with an inlet of a water heater (102) and the second valve (112) is in fluid communication with an outlet of the water heater (102), to permit water to drain from the water heater (102) upon both, 1, loss of electric power to the water heater (102), and, 2, a temperature of a fluid in or around the water heater (102) being less than or equal to a predetermined low temperature threshold.
  15. The method of claim 14, wherein the first valve (110) and the second valve (112) are configured to transition: from an open state to a closed state when, 1, the electric power is lost to the water heater and, 2, the temperature of the fluid is less than or equal to the predetermined low temperature threshold, such that in the closed state water is prevented from flowing into the water heater (102); and from a closed state to an open state when, 1, the electric power is restored to the water heater (102), or, 2, the temperature of the fluid is greater than the predetermined low temperature threshold, such that in the open state water is permitting to flow into the water heater (102).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 63/302,167, filed January 24, 2022. FIELD OF TECHNOLOGY The present invention relates generally to valves and systems for preventing damage caused by water freezing in piping systems and, more particularly, to freeze protection valves and systems for tankless water heaters. BACKGROUND Tankless water heating systems, including gas and electric-based tankless water heaters, are commonly installed in locations where the tankless water heater can be exposed to low ambient temperatures. For example, tankless water heaters are often installed on the outside of a home or building, or inside of a home or building such as in an attic, or in a garage. Although these locations may be convenient installation locations and are good for providing sufficient ventilation for gas-fired tankless water heaters, installing a tankless water heater in a location susceptible to low ambient temperatures can increase the risk that the tankless water heater becomes damaged due to water freezing within the tankless water heater. It is common for a heat exchanger of a tankless water heater to become damaged when water freezes and expands within the heat exchanger, often resulting in an expensive repair or replacement of the heat exchanger. To help reduce the likelihood that the tankless water heater becomes damaged due to freezing water, some tankless water heaters include resistive heating elements or heat tape configured to heat the water and/or piping of the tankless water heater when a low ambient temperature is detected. Other tankless water heaters include control functions configured to periodically fire the gas burner to heat the water in the tankless water heater and prevent the water from freezing. Such resistive heating systems or gas heating methods are inefficient and tend to increase the overall operational cost of the tankless water heater. Furthermore, these heating methods are rendered inoperable during a power outage because the tankless water heater is unable to control the resistive heating elements or the ignition system of the gas burner. Therefore, if a power outage occurs in low ambient temperatures (e.g., during an ice storm or a snowstorm), the tankless water heater may be unable to operate and can be damaged if the water in the tankless water heater freezes. Some existing freeze protection systems include drains and valves that allow the water to drain from the tankless water heater, thereby preventing the tankless water heater from being damaged by expanding frozen water. Unfortunately, many of these freeze protection systems require manual manipulation of the valves to drain the water. Manually draining the water from the tankless water heater can be a cumbersome task and is often forgotten or overlooked by homeowners. Other freeze protection systems include valves that can automatically actuate when the temperature of the ambient air or the water reaches near-freezing temperatures (e.g., 35 °F). These automatic valves, however, are designed to open even if power is still supplied to the tankless water heater. As will be appreciated, a loss of hot water every time the ambient temperature approaches the freezing temperature of water, even if no power is lost, is not desirable. Furthermore, other freeze protection systems that utilize solenoid valves are designed to automatically open upon a loss of power. Unfortunately, automatically draining the water upon each loss of power, including a brief loss of power or a loss of power when the ambient temperature is greater than the freezing temperature of water, is impractical. Accordingly, an improved tankless water heater is needed that is capable of providing freeze protection in the event of low ambient temperature conditions and loss of electrical power. US 4,621,679 discloses a valve for a water temperature control system having a heat exchanger, a tank, and a pump for circulating heat transfer fluid through a supply line from the tank to the heat exchanger and through a return line from the heat exchanger to the tank including a valve housing interposed in both the supply line and the return line having supply inlet and supply outlet connections, having return inlet and return outlet connections, and having first and second drain connections, a valve element associated with the valve housing having a first position for normally circulating the heat transfer fluid from the supply inlet connection to the supply outlet connection and from the return inlet connection to the return outlet connection and having a second position discontinuing circulation through the supply inlet connection and the return outlet connection and connecting the supply outlet connection to the first drain connection and the return outlet connection to the second drain connection. Actuation is provided for moving the valve element to the second position upon the occurrence of a