Plumbers, Showers, Taps and Heating systems

Plumber - Dating from the Roman Empire
The word plumber dates from the Roman Empire. In Roman times, some roofs were made of lead, or plumbum in Latin (hence the periodic table of the elements symbol of 'Pb' for lead). Lead roofs were waterproof, and the workers on such roofs were what are now called "plumbers". Roman baths later used lead for piping and for the main baths. Thus, a person with expertise in working with lead was known as a Plumbarius, eventually shortened to plumber.
A plumber is a tradesperson who specialises in installing and maintaining systems used for potable (drinking) water, sewage, drainage, or industrial process plant piping. Years of training and/or experience are needed to become a skilled plumber; some jurisdictions also require that plumbers be licensed. A Master Plumber has demonstrated mastery of the trade of plumbing. The Master Plumber may have worked in a single area of the trade or may have experience in multiple areas of the plumbing trade.
Plumbing codes are strict, and need for quality plumbing work is high because of the health and safety problems associated with poor water supply and sewage removal.
Plumbers in the United Kingdom undertake the installation of domestic internal hot and cold water pipe work, sanitary fittings and related soil and waste pipe work systems. Domestic, commercial and industrial gas-fired (central) heating installation, servicing and repair works, and works related to all other gas fired appliances, although done by plumbers, may also involve other trades such as pipe fitters, gas fitters etc.
Oil fired heating appliance installation, servicing and maintenance works must be undertaken by OFTEC registered individuals and companies in order to operate in the UK.
Central Heating
A central heating system provides warmth to the whole interior of a building (or portion of a building) from one point to multiple rooms. When combined with other systems in order to control the building climate, the whole system may be a HVAC (heating, ventilation and air conditioning) system.
Central heating differs from local heating in that the heat generation occurs in one place, such as a furnace room in a house or a mechanical room in a large building (though not necessarily at the "central" geometric point). The most common method of heat generation involves the combustion of fossil fuel in a furnace or boiler. The resultant heat then gets distributed: typically by forced-air through ductwork, by water circulating through pipes, or by steam fed through pipes. Increasingly, buildings utilize solar-powered heat sources, in which case the distribution system normally uses water circulation.
In much of northern Europe and in urban portions of Russia, where people seldom require air conditioning in homes due to the temperate climate, most new housing comes with central heating installed. Such areas normally use gas heaters, district heating, or oil-fired systems. In the western and southern United States natural-gas-fired central forced-air systems occur most commonly; these systems and central-boiler systems both occur in the far northern regions of the USA. Steam-heating systems, fired by coal, oil or gas, feature in the USA, Russia and Europe: primarily for larger buildings. Electrical heating systems occur less commonly and are only practical with low cost electricity or when geothermal heat pumps are used. Considering the combined system of central generating plant and electric resistance heating, the overall efficiency will be less than for direct use of fossil fuel for space heating.
Bathroom design
The design of a bathroom must account for the use of both hot and cold water, in significant quantities, for cleaning the human body. The water is also used for moving solid and liquid human waste to a sewer or septic tank. Water may be splashed on the walls and floor, and hot humid air may cause condensation on cold surfaces. From a decorating point of view the bathroom presents a challenge. Ceiling, wall and floor materials and coverings should be impervious to water and readily and easily cleaned. The use of ceramic or glass, as well as smooth plastic materials, is common in bathrooms for their ease of cleaning. Such surfaces are often cold to the touch, however, and so water-resistant bath mats or even bathroom carpets may be used on the floor to make the room more comfortable. Alternatively, the floor may be heated, possibly by strategically placing heater conduits close to the surface.
Electrical appliances, such as lights, heaters, and heated towel rails, generally need to be installed as fixtures, with permanent connections rather than plugs and sockets. This minimizes the risk of electric shock. Ground-fault circuit interruptor electrical sockets can reduce the risk of electric shock, and are required for bathroom socket installation by electrical and building codes in the United States and Canada. In some countries, such as the United Kingdom, only special sockets suitable for electric shavers are permitted in bathrooms, and are labelled as such.