Systems and methods for venting a water heater

Abstract

Systems and methods for venting a water heater are disclosed. The system includes a water heater, a blower, a draft hood, and a thermal switch. The blower has a blower inlet positioned to receive combustion gas from the water heater and a blower outlet positioned to exhaust combustion gas. The draft hood defines a passageway positioned to receive combustion gas from the blower outlet. The draft hood defines a relief opening to allow gas to enter into or exit from the passageway of the draft hood. The thermal switch detects a blockage in the passageway of the draft hood and deactivates the water heater when a blockage is indicated. A method for venting a water heater includes blowing exhaust gas outward through a blower outlet of the water heater, and receiving the exhaust gas blown through the outlet with a draft hood positioned on top of the blower outlet.

What is claimed: 
     
         1 . A vented water heating system comprising:
 a fuel-fired water heater having a combustion gas exhaust outlet;   a blower positioned to advance combustion gas exhausted from the combustion gas exhaust outlet of the fuel-fired water heater, the blower having a blower inlet positioned to receive combustion gas and a blower outlet positioned to exhaust combustion gas; and   a draft hood defining a passageway positioned to receive combustion gas exhausted from the blower outlet, the draft hood at least partially defining a relief opening positioned to allow gas to enter into or exit from the passageway of the draft hood; and   a thermal switch positioned to detect a blockage in the passageway of the draft hood and coupled to deactivate the water heater when a blockage is indicated.   
     
     
         2 . The system of  claim 1 , wherein the draft hood comprises a flared portion oriented toward the blower outlet; and the system further comprises:
 a pipe extending from a narrow end of the flared portion of the draft hood and in a direction generally away from the outlet of the fuel-fired water heater.   
     
     
         3 . The system of  claim 2 , wherein the flared portion of the draft hood is concentric with the blower outlet. 
     
     
         4 . The system of  claim 1 , wherein the draft hood is spaced from the blower outlet to at least partially define the relief opening and enable communication of combustion gas exhausted by the blower outlet with atmosphere surrounding the draft hood. 
     
     
         5 . The system of  claim 1 , the thermal switch being calibrated to interrupt operation of the water heater when a temperature above a predetermined limit is sensed. 
     
     
         6 . The system of  claim 1 , wherein the thermal switch is coupled to the draft hood. 
     
     
         7 . The system of  claim 1 , wherein thermal switch is positioned proximal the relief opening. 
     
     
         8 . A kit for venting a water heater comprising:
 a draft hood configured to be coupled to the water heater downstream from a blower outlet of the water heater in a direction of exhaust gas flow, the draft hood being configured to receive the exhaust gas blown through the blower outlet; and   a thermal switch couplable proximal the draft hood, the thermal switch configured to be electrically coupled to the water heater, the thermal switch being calibrated to shut down the water heater when the thermal switch senses a temperature above a predetermined limit.   
     
     
         9 . The kit of  claim 8 , wherein the draft hood comprises a flared portion opening toward the blower outlet when the draft hood is attached to the water heater; and the kit further comprises:
 a pipe extending from a narrow end of the flared portion of the draft hood and away from the water heater when the draft hood is attached to the water heater.   
     
     
         10 . The kit of  claim 9 , wherein the flared portion is configured to be attached to the water heater concentrically with the blower outlet. 
     
     
         11 . The kit of  claim 8 , wherein the draft hood is spaced from the blower outlet by one or more relief openings when the draft hood is coupled to the water heater, the relief openings enabling communication of the exhaust gas blown through the blower outlet with atmosphere surrounding the draft hood. 
     
     
         12 . The system of  claim 8 , wherein the draft hood comprises a flared portion opening toward the blower outlet when the draft hood is attached to the water heater, and the thermal switch is directly coupled to one of the flared portion or one or more mounting structures coupled to the flared portion. 
     
     
         13 . The system of  claim 8 , wherein the draft hood is spaced from the blower outlet by one or more relief openings when the draft hood is attached to the water heater, and the thermal switch is positioned to be adjacent or within one of the relief openings. 
     
     
         14 . A method for venting a water heater comprising:
 blowing exhaust gas outward through a blower outlet of the water heater;   receiving the exhaust gas blown through the outlet with a draft hood positioned downstream of the blower outlet;   sensing a temperature adjacent the draft hood with a thermal switch; and   deactivating the water heater when the thermal switch senses a temperature above a predetermined limit.   
     
     
         15 . The method of  claim 14 , wherein the draft hood comprises a flared portion opening toward the blower outlet, and the receiving step comprises:
 receiving the exhaust gas blown through the blower outlet with the flared portion of the draft hood.   
     
     
         16 . The method of  claim 15 , wherein the flared portion is positioned concentrically with the blower outlet. 
     
     
         17 . The method of  claim 14 , wherein the draft hood is spaced from the blower outlet by one or more relief openings, and the method further comprises:
 enabling communication of the exhaust gas blown through the blower outlet with atmosphere surrounding the draft hood via the relief openings.   
     
     
         18 . The method of  claim 14 , wherein the draft hood comprises a flared portion opening toward the blower outlet, and the sensing step comprises:
 sensing the temperature at a position immediately adjacent the flare portion of the draft hood.   
     
     
         19 . The method of  claim 14 , wherein the draft hood is spaced from the blower outlet by one or more relief openings, and the sensing step comprises:
 sensing the temperature at a position adjacent or within the relief openings.   
     
     
         20 . A method for configuring a vented water heating system to detect a blockage in a passageway of a draft hood, the method comprising:
 positioning a thermal switch downstream of a blower of the water heating system, the thermal switch being positioned to detect a blockage in the passageway of the draft hood; and   coupling the thermal switch to the water heating system such that the thermal switch is operable to shut down the water heating system when the thermal switch senses a temperature above a predetermined limit.