Fuel-fired water heater with flammable vapor sensor and associated induced flow tube

摘要

Fuel fired power vented and natural draft type water heaters are provided with flammable vapor sensors operative to detect flammable vapors exteriorly adjacent the water heater and responsively preclude fuel flow to the burner portion of the water heater. In each water heater a flow tube is extended between the flammable vapor sensor and the draft structure of the water heater and forms a flow path isolated from the combustion chamber of the water heater. In the event that flammable vapors are present exteriorly adjacent the water heater, the forced or natural draft of the water heater creates a biased flow of flammable vapors which is sequentially drawn across the vapor sensor and through the isolated flow path to the draft structure of the water heater.