Apparatus for heating, refrigerating, ventilating, steam generating, drying, cooking, water supply and sanitary purposes; apparatus and installations for air conditioning, ventilation, heating and cooling; apparatus and installations for heating including gas heating, central heating, floor heating systems, space heaters, portable electric heaters, heating elements, lamps, fireplaces, gas and wood burning stoves, heat exchangers, artificial gas logs, heating units for propagating seeds and plants, heating plates, mats, cushions and pads, incubators, dryers, bed-warmers, electric blankets, radiators, humidifiers; apparatus and installations for cooling including air conditioners, air-conditioning installations, evaporative coolers, ice machines and apparatus, refrigerated coolers and cabinets and chambers, fans; thermostats therefor; and parts, fittings and accessories therefor