Abstract: A mechanism for attaching a gas controller to a water heater includes a shank that is longitudinally received in a spud attached to the water heater. O-rings serve to form a water tight seal between the interior surface of the spud and the exterior surface of the shank. Slots formed in the spud and a groove formed in the shank allow the two components to be axially locked to one another with the insertion of a retainer spring clip. The spring clip is readily removable to allow the two components to be separated without the destruction of any components.

Abstract: A device for preventing the inadvertent rotation of a temperature selection dial associated with the temperature controller of a water heater. The device includes a spring-loaded prong that extends across the face of a rotatable dial so as to prevent rotation of thereof. The force required to pry the prong off of the dial is selected to be greater than what a small child is typically capable of exerting.

Abstract: A furnace diagnostic system includes sensors that monitor various functions of the furnace. Data generated by such sensors may be stored for subsequent transfer or may be transferred in real time via an infra red link to a remote handheld device with which an analysis thereof is performed. The handheld device additionally allows the technician to control various furnace functions to facilitate the generation of relevant real time data. In order to further enhance the system's diagnostics capabilities, the communication may be established with a centralized computing facility which includes a data base containing data relating to an entire population of similar furnaces.

Abstract: A safety device for shutting off the flow of gas to a gas-fired appliance in the presence of flammable vapors. A flammable vapor sensor is inserted in the circuit supplying a solenoid actuated valve with power from a thermocouple. The sensor responds to the presence of a flammable vapor with an increase in resistance. When a critical concentration of flammable vapors is achieved, the voltage drop across the sensor causes the solenoid actuated valve to close.

Abstract: A safety device for shutting off the flow of gas to a gas-fired appliance in the presence of flammable vapors. The resistance of a variable resistance flammable vapor sensor is monitored by a microprocessor that controls the operation of a gas flow valve. When the measured resistance indicates the presence of a preselected concentration of flammable vapors, the gas flow valve is shut of and the ignition system cannot be energized.