A system to reduce standby losses in a hot water heater is presented. The system utilizes a dual safety relay valve between the combination gas controller and the burner. The dual safety relay valve bypasses gas to a rotary damper actuator valve to position a damper flapper valve located over/inside the flue pipe. Once the flapper valve has opened to ensure combustion, the gas is allowed to flow back to the dual safety relay valve. Some of the bypass gas may be diverted to boost the pilot or to supply a booster. The dual safety relay valve is then opened to allow the gas supply to the burner. Once the burner is turned off, bypass gas bleeds out of the rotary damper actuator valve to close the damper flapper valve to reduce standby losses through the flue pipe, and to allow the dual safety relay valve to close tightly.

A system to reduce standby losses in a hot water heater is presented. The system utilizes a dual safety relay valve between the combination gas controller and the burner. The dual safety relay valve bypasses gas to a rotary damper actuator valve to position a damper flapper valve located over/inside the flue pipe. Once the flapper valve has opened to ensure combustion, the gas is allowed to flow back to the dual safety relay valve. Some of the bypass gas may be diverted to boost the pilot or to supply a booster. The dual safety relay valve is then opened to allow the gas supply to the burner. Once the burner is turned off, bypass gas bleeds out of the rotary damper actuator valve to close the damper flapper valve to reduce standby losses through the flue pipe, and to allow the dual safety relay valve to close tightly.

A heating apparatus can have a sealed combustion chamber, a burner, and various air channels to direct air into the sealed combustion chamber and to provide heated air to the desired area or environment such as an interior room. A channel can direct a flow of air along a face of the sealed combustion chamber to cool the face. The channel can be within or outside of the sealed combustion chamber. Alternatively, or in addition, the heating apparatus can be capable of operating as a direct vent device or as a vent free device.

A heating apparatus can have a sealed combustion chamber and a burner. The heating apparatus can have an air shutter that controls the amount of air that mixes with fuel directed toward the burner. The air shutter can be controlled by rotating a shaft that connects to the air shutter. The heating apparatus can also have a system of channels along its front face which direct air along the front face.

Methods, burner, apparatuses, and systems are provided for controlling a velocity of a jet of gas exiting a burner when the gas is heated or not and at a corresponding second higher temperature or lower first temperature. Through the use of a temperature-sensitive magnetic valve, the flow of a gas can be redirected to maintain velocity of the gas as delivered to a combustion chamber based on the temperature of the gas. The temperature-sensitive magnetic valve can redirect flow of the gas based on the magnetic state of a ferromagnetic material. The state of the temperature-sensitive magnetic valve changes based on the temperature of the gas to maintain the velocity of the gas delivered through an outlet of the burner to the combustion chamber. Thus, heated gases and standard temperature gases can be delivered at approximately equal velocities thus maintaining flame size and shape.

In a premixing apparatus for mixing a fuel gas with air and supplying an air-fuel mixture to a burner through a fan, a downstream end of a gas supply passage is connected to a gas suction portion that is provided in an air supply passage which is located on an upstream side of the fan, and a butterfly valve is provided in a portion of the passage, which is located on an upstream side from the gas suction portion, and is rotatable to at least an open attitude and a closed attitude. At least one ventilation opening through which air flows from an upstream side to a downstream side of the valve at the closed attitude is formed in the valve, and a size of the valve is set so that, at the closed attitude, a clearance between an outer peripheral edge of the valve and a peripheral wall surface of the passage is substantially closed.

In a premixing apparatus for mixing a fuel gas with air and supplying an air-fuel mixture to a burner through a fan, a downstream end of a gas supply passage is connected to a gas suction portion that is provided in an air supply passage which is located on an upstream side of the fan, and a butterfly valve is provided in a portion of the passage, which is located on an upstream side from the gas suction portion, and is rotatable to at least an open attitude and a closed attitude. At least one ventilation opening through which air flows from an upstream side to a downstream side of the valve at the closed attitude is formed in the valve, and a size of the valve is set so that, at the closed attitude, a clearance between an outer peripheral edge of the valve and a peripheral wall surface of the passage is substantially closed.

A non-return valve for a flow channel has a housing and an outflow opening that can be closed by a pivoting blocking flap. The blocking flap has a dome-shaped bulge. An opening edge of the outflow opening has a hinge region for the blocking flap that transitions into a blocking flap stop region circumferentially opposite the hinge region. The blocking flap stop region is offset so that the opening edge has a progression that is curved in the circumferential direction and in the outflow direction. The housing has an indentation in the circumferential direction, which is not closed by the blocking flap such that the indentation forms a condensate chamber when the housing is inserted into the surrounding flow channel. The indentation is equipped with a flow opening, through which a condensate accumulating in the condensate chamber delimited by the indentation can flow in the interior of the housing.

An electronic control device includes: a flow rate calculation unit that calculates a flow rate of intake air based on an output signal of a flow rate measurement device assembled to an intake pipe; a flow rate correction value calculation unit that calculates an average value, a maximum value, and a minimum value of the flow rate of the intake air, calculated by the flow rate calculation unit, during a predetermined period, and an amplitude of a signal with one or more frequencies equal to or higher than a fundamental frequency of the output signal of the flow rate measurement device and included in the output signal of the flow rate measurement device, and calculates a correction value for the flow rate of the intake air based on calculation results; and a flow rate correction unit that corrects the flow rate of the intake air based on the correction value.

An electronic control device includes: a flow rate calculation unit that calculates a flow rate of intake air based on an output signal of a flow rate measurement device assembled to an intake pipe; a flow rate correction value calculation unit that calculates an average value, a maximum value, and a minimum value of the flow rate of the intake air, calculated by the flow rate calculation unit, during a predetermined period, and an amplitude of a signal with one or more frequencies equal to or higher than a fundamental frequency of the output signal of the flow rate measurement device and included in the output signal of the flow rate measurement device, and calculates a correction value for the flow rate of the intake air based on calculation results; and a flow rate correction unit that corrects the flow rate of the intake air based on the correction value.