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: 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: 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.

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.

Abstract: An adjustable flow limiter for adjustably limiting flow, for example through the vent of a diaphragm-type fluid flow regulator. The adjustable flow limiter has a housing with a compartment therein, and first and second ports communicating with the compartment, the ports and the compartment defining a flow passage through the housing. A foam body is disposed in the compartment in the flow path, and a compressor, preferably in the form of a threaded member, can selectively compress the foam body to adjust the flow rate through the flow passage.