Abstract: A shelf unit (3, FIG. 1) for a refrigerator cabinet includes an air flow passageway (6) connectible to a duct (1) located at the rear of the refrigerator. The flow of air through the passageway (6) is regulated by a flap whose movement is controlled by a thermostat (9) also mounted upon the shelf. The shelf unit, when in position in a refrigerator, enables a user to preset the temperature of the zone in the refrigerator cabinet beneath the unit.

Abstract: A flame failure device for a gas-fired appliance has a heat sensitive device (24') in the form of fine bore tube (25). The tube is connected to one chamber (10) of a pressure sensitive gas flow control valve assembly. The chamber is pressurized and the rate of flow from the chamber is controlled by flow through the fine bore tube (25) the application of heat to which reduces the rate of flow through the fine bore tube (25) while the withdrawal of heat restores the rate of flow. Heat is provided by a gas burner of the appliance. The fine bore tube may have a non-circular cross-section and be formed by deforming part at least of a length of tubing (FIGS. 4A and 5B).

Abstract: A control unit for a gas-fired water heater comprises a resiliently-loaded main valve for controlling gas flow to a gas burner of the heater, the main gas valve being opened and closed by a flexible diaphragm exposed to pressure of water flowing through the water heater. A subsidiary gas valve located upstream in the gas supply of the main gas valve has a permanently open by-pass and is actuable by a user operated control which also adjusts the resilient loading of the main gas valve in such manner as to adjust the rate of water flow and the rate of gas flow to provide hot water of a required temperature and at a required rate of flow.

Abstract: A gaseous fuel mixture burner which includes a mixer device into which gas is injected so as to provide a gaseous vortex formation within the mixer, air being drawn into the device and mixed with the gas by the low pressure region created within the vortex.

Abstract: A coating composition suitable for application to the internal surfaces of ovens to render these self cleaning comprising a milled self-matting devitrifying enamel frit and antimony trioxide or a precursor thereof, preferably together with an oxidation catalyst comprising an oxide of copper, manganese or cobalt. The coating adheres directly to metal surfaces and avoids the necessity for first applying a ground coat.