Disclosed are systems and methods for automated furnace inducer sensor output verification. A furnace may include a sensor, such as a transducer, that may be used to measure pressure within the furnace (for example, pressure resulting from the operation of a draft inducer blower and/or any other component of the furnace). It is possible that the data produced by the sensor may remain relatively fixed for a given period of time. However, this makes it difficult to determine if the data is valid or if the sensor is malfunctioning. Given this, an algorithm is used to change a motor speed of the inducer blower. The subsequent data that is produced by the sensor is then monitored to determine if an expected change in the data occurs. If the change does not occur, then it may be determined that the sensor is malfunctioning.

Disclosed is an induced-draft gas-fired furnace that includes: an electronic furnace controller, a burner assembly, a gas valve, and an inducer motor, wherein the controller: accelerates the inducer motor at a first pre-ignition rate to a first pre-ignition speed; controls the gas valve to supply gas to the burner assembly to obtain a first pre-ignition ratio of fuel to air, operates an igniter to attempt to ignite the first fuel mixture, determines whether fuel has ignited in the burner assembly, wherein when fuel having the first pre-ignition ratio of fuel to air remains unignited after a plurality of ignition attempts, the controller: decelerates the inducer motor to a second pre-ignition rate to obtain a second pre-ignition speed and a second fuel mixture comprising a second pre-ignition ratio of fuel to air, and determines whether the second fuel mixture has ignited in the burner assembly.

A system for changing a bias level of a flame sensing circuit to identify leakage in the flame sensing circuit. The bias level may be varied in the positive or negative axis and the flame current may be noted to identify leakage. The bias level may be changed by a microcontroller. The bias level may be changed using an operational amplifier configuration which is used as a signal conditioner for interfacing the flame signal to the microcontroller.

A water heater may include a water tank, a burner, a pilot for igniting the burner, an ignitor for igniting the pilot, a thermoelectric device in thermal communication with a flame of the pilot, a controller for controlling an ignition sequence of the pilot using the ignitor, and a rechargeable power storage device for supplying power to the ignitor and the controller. The rechargeable power storage device may be rechargeable using the energy produced by the thermoelectric device. The controller is configured to selectively run only the pilot for at least part of a heating cycle to increase the recharge time of the rechargeable power storage device while still heating the water in the water heater.

A flame analytics system that may incorporate a burner, one or more sensors at the burner, a historical database connected to the one or more sensors, a model training module connected to the historical database, and a runtime algorithm module connected to the one or more sensors and the model training module. The runtime algorithm may compare realtime data from the one or more sensors and historical data from the model training module in accordance with a machine learning algorithm. The system may further incorporate a fault detection module connected to the runtime algorithm module, a fault diagnostics module connected to the fault detection module, and an enunciator connected to the fault detection module. The one or more sensors may also include having video or acoustic sensitivity of combustion in the burner.

A flue gas analyser for determining the efficiency of a burner burning a supply gas and producing a flue gas by: calculating an efficiency of the burner based on a detected amount of a first target gas in the flue gas and an expected amount of the first target gas in the flue gas; predicting an amount of a second target gas in the flue gas based on the efficiency of the burner; estimating a composition of the supply gas based on a detected amount of the second target gas in the flue gas and the predicted amount of the second target gas in the flue gas; and correcting the calculated efficiency of the burner based on the estimated composition of the supply gas.

A flow control apparatus includes a flow control signal generation device for generating a DC control signal based on an audio signal and at least one proportional valve. The flow control signal generation device includes an audio receiving module, a filter rectifier module, a microprocessor and a proportional valve control signal generation module. The filter rectifier module generates at least one DC audio signal by filtering the audio signal provided by the audio receiving module. The microprocessor generates a plurality of period attenuated values based on the DC audio signal. The proportional valve control signal generation module filters the audio signal, attenuates the signal based on the period attenuated values, and then performs filtering and rectification processing to generate the DC control signal, such that the proportional valve may control the opening ratio of the proportional valve based on the DC control signal.

A method includes identifying a first steady-state gain associated with a relationship between a characteristic of a furnace and a setpoint used by a controller that is configured to control the characteristic of the furnace, The first steady-state gain is identified using data collected when the furnace is not suffering from flooding. The method also includes identifying a second steady-state gain associated with the relationship during operation of the furnace. The method further includes comparing the first and second steady-state gains and identifying actual or potential flooding of the furnace based on the comparison.

A water heater may include a water tank, a burner, a pilot for igniting the burner, an ignitor for igniting the pilot, a thermoelectric device in thermal communication with a flame of the pilot, a controller for controlling an ignition sequence of the pilot using the ignitor, and a rechargeable power storage device for supplying power to the ignitor and the controller. The rechargeable power storage device may be rechargeable using the energy produced by the thermoelectric device. The controller is configured to selectively run only the pilot for at least part of a heating cycle to increase the recharge time of the rechargeable power storage device while still heating the water in the water heater.

A heating control device including input/output ports, a memory operable to store smoke output thresholds, and a microprocessor. The microprocessor is configured to transmit a first electrical signal to operate an air circulation fan at a first speed and a heating unit in a first configuration to burn a lubricant at a first temperature where less than all of the burners are active. The microprocessor is further configured to obtain a smoke output measurement for the first temperature, compare the smoke output measurement to the smoke output threshold, and transmit a second electrical signal to transition the air circulation fan to a second speed to burn the lubricant at a second temperature that is greater than the first temperature when the smoke output measurement is less than the smoke output threshold and is less than the first temperature when the smoke output measurement is greater than the smoke output threshold.