Abstract: A control system for a water heater generally includes a water heater controller configured to receive upper and lower sensor temperatures associated with water in the respective upper and lower portions of the tank. The water heater controller is configured to determine a value indicative of a portion of water in the tank at a desired set-point temperature as a function of the upper sensor temperature, the lower sensor temperature, and the desired set-point temperature. The water heater controller is configured to wirelessly transmit at least one signal indicative of said value indicative of the portion of water in the tank at the desired set-point temperature. A user interface includes a plurality of selectively illuminated segmented portions. The user interface is configured to receive said value from the water heater controller and to selectively illuminate a number of segmented portions representative of said value.

Abstract: A thermostat is provided that receives one or more inputs from at least one heating system of a climate control system, and initiates an appropriate action in response to the input. The thermostat can turn off a heat pump providing substandard heat and responsively turn on a fuel-fired auxiliary furnace. The thermostat may discontinue further operation of the auxiliary furnace upon receiving an operating error signal associated with the auxiliary furnace, and responsively turn on the heat pump to provide for continued heating. The thermostat may also discontinue operation of the fuel-fired furnace and turn on a circulating fan in response to an input signal indicating a furnace high-temperature or a carbon monoxide presence.

Abstract: A control system for a water heater generally includes a water heater controller configured to receive upper and lower sensor temperatures associated with water in the respective upper and lower portions of the tank. The water heater controller is configured to determine a value indicative of a portion of water in the tank at a desired set-point temperature as a function of the upper sensor temperature, the lower sensor temperature, and the desired set-point temperature. The water heater controller is configured to wirelessly transmit at least one signal indicative of said value indicative of the portion of water in the tank at the desired set-point temperature. A user interface includes a plurality of selectively illuminated segmented portions. The user interface is configured to receive said value from the water heater controller and to selectively illuminate a number of segmented portions representative of said value.

Abstract: A control for a water heater is provided that comprises a pressure switch for sensing a predetermined level of airflow sufficient for maintaining proper burner operation, and a temperature sensing means for sensing the temperature of the water in the tank. The control further comprises a processor for controlling the operation of the burner to maintain the water temperature above a predetermined value. When the processor receives a signal from the pressure switch or temperature switch indicating a malfunction, the processor shuts down the burner and subsequently attempts to restart the burner. The processor will lock-out further burner operation after a predetermined number of consecutive shut downs occurs, and will communicate any malfunction information to a remote display device.

Abstract: A control for controlling the operation of a fuel-fired heating appliance is provided that include a sensor capable of sensing the presence of carbon monoxide gas and providing an output indicative of the level of carbon monoxide gas. The control further includes a microprocessor that periodically reads the CO sensor output and stores at least one sensor output value in a memory, wherein the microprocessor responsively discontinues the operation of the appliance when the microprocessor detects a sensor output that has increased by more than a predetermined amount over at least one previously stored sensor output value. In one embodiment, the control is preferably configured to periodically read the sensor output value, and responsive discontinue operation of an appliance upon sensing a predetermined increase of at least a 50 percent increase over the previously monitored sensor output value over a period of about 15 to 90 minutes.

Abstract: A control for controlling the operation of a fuel-fired heating appliance is provided that include a sensor capable of sensing the presence of carbon monoxide gas and providing an output indicative of the level of carbon monoxide gas. The control further includes a microprocessor that periodically reads the CO sensor output and stores at least one sensor output value in a memory, wherein the microprocessor responsively discontinues the operation of the appliance when the microprocessor detects a sensor output that has increased by more than a predetermined amount over at least one previously stored sensor output value. In one embodiment, the control is preferably configured to periodically read the sensor output value, and responsive discontinue operation of an appliance upon sensing a predetermined increase of at least a 50 percent increase over the previously monitored sensor output value over a period of about 15 to 90 minutes.

Abstract: A control for controlling the operation of a fuel-fired heating appliance is provided that include a sensor capable of sensing the presence of carbon monoxide gas and providing an output indicative of the level of carbon monoxide gas. The control further includes a microprocessor that periodically reads the CO sensor output and stores at least one sensor output value in a memory, wherein the microprocessor responsively discontinues the operation of the appliance when the microprocessor detects a sensor output that has increased by more than a predetermined amount over at least one previously stored sensor output value. In one embodiment, the control is preferably configured to periodically read the sensor output value, and responsive discontinue operation of an appliance upon sensing a predetermined increase of at least a 50 percent increase over the previously monitored sensor output value over a period of about 15 to 90 minutes.

Abstract: A control for a water heater is provided that comprises a pressure switch for sensing a predetermined level of airflow sufficient for maintaining proper burner operation, and a temperature sensing means for sensing the temperature of the water in the tank. The control further comprises a processor for controlling the operation of the burner to maintain the water temperature above a predetermined value. When the processor receives a signal from the pressure switch or temperature switch indicating a malfunction, the processor shuts down the burner and subsequently attempts to restart the burner. The processor will lock-out further burner operation after a predetermined number of consecutive shut downs occurs, and will communicate any malfunction information to a remote display device.

Abstract: A method of controlling a gas-fired water heater. A resistance input is received from a sensor configured to sense flammable vapor near the heater tank. The resistance input is compared to one or more previously received inputs from the sensor. Based on the comparing, one or more functions of the heater are controlled. This control method can be used to compensate for gradual ageing of the sensor.

Abstract: An apparatus for operating a gas valve in a gas-fired heating system includes a solenoid having a pick coil and a hold coil connected to the pick coil and to a thermo-generator. A power supply powers the pick coil to open the gas valve. The thermo-generator powers the hold coil to hold the gas valve open. The apparatus is small and inexpensive compared to systems that use DC-DC converters and/or stepper motors to operate a millivolt valve. A millivolt valve can be operated via power from a heater thermostat, without AC power having to be wired to the heater.

Abstract: A controller is provided for controlling the operation of a gas-fired water heating appliance. In one embodiment of the present invention, a controller is provided that comprises a switching means for connecting an electrical power source to an igniter for igniting gas, a voltage sensing means for sensing the voltage value of the electrical power source, and a processor that is capable of determining whether the power source is of a first rated voltage level or a second rated voltage level. The processor is capable of responsively selecting an appropriate switching sequence from a look-up table having a plurality of switching sequences corresponding to a plurality of voltage values for either the first rated voltage or the second rated voltage, where the processor controls the switching means based on the selected switching sequence to effect switching of power to supply an average predetermined voltage to the igniter that will heat the igniter to a desired temperature.

Abstract: One or more embodiments of a controller for controlling a fuel-fired water heater are provided that are able to detect a high rate of temperature change condition in the water heater tank. The fuel fired water heater appliance having a water storage vessel comprises a surface mount sensor disposed on the outer surface of the storage vessel near the bottom of the vessel, for sensing the temperature of the vessel. The controller monitors the rate of change of the temperature sensed by the surface mount sensor during a heating cycle, and discontinues operation of the water heater appliance upon detecting an increase in the rate of temperature change that is indicative of an undesirable level of sediment build-up in the water storage vessel.

Abstract: A control system for a fuel-fired water heater appliance is provided that includes a control for the appliance that is in communicating with a sensor for sensing a water flow rate through the water heater. The control system is capable of controlling a gas valve to supply fuel to a burner at a maximum rate of fuel flow when the water flow rate is determined to be above a predetermined threshold. The control system is capable of controlling the gas valve to supply fuel to a burner at a reduced rate of fuel flow when the water flow rate is below a predetermined threshold, whereby the control 128 establishes the lower rate of heating operation as long as the temperature of the heated water is below the predetermined maximum temperature.

Abstract: A control system for a fuel-fired water heater appliance is provided that includes a control for the appliance that is in communicating with a sensor for sensing a water flow rate through the water heater. The control system is capable of controlling a gas valve to supply fuel to a burner at a maximum rate of fuel flow when the water flow rate is determined to be above a predetermined threshold. The control system is capable of controlling the gas valve to supply fuel to a burner at a reduced rate of fuel flow when the water flow rate is below a predetermined threshold, whereby the control 128 establishes the lower rate of heating operation as long as the temperature of the heated water is below the predetermined maximum temperature.

Abstract: A controller for a fuel-fired heating appliance is provided that includes at least one sensor for detecting the presence of at least one of a flammable vapor or a carbon monoxide gas. The controller includes a transmitter module for wirelessly transmitting digital signals, and a microprocessor for controlling the operation the fuel-fired heating appliance. The microprocessor is in communication with the transmitter module, and is capable of monitoring the at least one other sensor for detecting an abnormal condition, and responds to an abnormal condition by communicating a message to the transmitter module. The transmitter module transmits the message to a thermostat that is capable of immediately displaying the message to alert an occupant of the abnormal condition.

Abstract: One or more embodiments of a controller for controlling a fuel-fired water heater are provided that are able to detect a high rate of temperature change condition in the water heater tank. The fuel fired water heater appliance having a water storage vessel comprises a surface mount sensor disposed on the outer surface of the storage vessel near the bottom of the vessel, for sensing the temperature of the vessel. The controller monitors the rate of change of the temperature sensed by the surface mount sensor during a heating cycle, and discontinues operation of the water heater appliance upon detecting an increase in the rate of temperature change that is indicative of an undesirable level of sediment build-up in the water storage vessel.

Abstract: An apparatus is provided for controlling the operation of a gas fired appliance having a gas valve circuit for enabling the flow of gas to the burner. The apparatus comprises a sensor capable of detecting the presence of flammable vapor, a switching means in series with the gas valve solenoid circuit for interrupting a thermocouple voltage to the gas valve solenoid to disable the flow of gas, and a fuse that normally conducts a current to the switching means to maintain the switching means in a conductive state for applying a thermocouple voltage to the gas valve solenoid. In response to the detection by the sensor of the presence of a predetermined level of flammable vapor concentration, a second switch supplies a higher current through the fuse. The higher current causes the fuse to blow and interrupt the current for maintaining the switching means in a conductive state, such that the switching means interrupts the thermocouple voltage applied to the gas valve solenoid to shut off the gas to the burner.

Abstract: A chemiresistor sensor probe for detecting target analytes. The probe includes a body having a first control surface and a second control surface recessed within the first. A sensor film comprises numerous conductive particles disposed upon the second surface. The film swells upon absorbing one or more analytes for which it has an affinity, thus causing the conductive particles to become more dispersed and increasing the resistance between the particles. The thickness of the film is equal to the distance between the first surface and the second surface, thus permitting the thickness to be controlled by varying the distance between the control surfaces. The robustness of the sensor probe is enhanced by placing a porous or mesh electrode along with, or in place of, a chemical binding agent between the film and the terminals. The robustness is also improved by placing a diode in series with the sensor circuit.

Abstract: An apparatus comprising a switch, a fuse, and a sensor that is capable of detecting the presence of flammable vapors and responsively changing in resistance, wherein the sensor enables the switch to supply current to the fuse which opens to shut down an appliance burner. The fuse is connected in series with a control circuit that enables a gas valve to supply gas to the burner 65. The apparatus comprises a voltage divider circuit that includes the sensor, which upon exposure to flammable vapors, increases in resistance to provide a voltage input to the gate of a FET 100. The FET switches on and conducts a current that blows the fuse to interrupt the appliance burner control circuit and shut down burner operation.

Abstract: A gas-powered water heater includes means for stepping down a line voltage from a receptacle remote from the tank, means for using the stepped down voltage to provide a low voltage, and means for using the low voltage to sense conditions pertaining to the heater and to control heater operation based on the sensed conditions. Using a plug-in transformer to provide power for microprocessor control makes it unnecessary to install a line voltage line to the heater.