The ancient Greeks originally developed central heating.
Circulating hot water can be used for central heating.Sometimes these systems are called hydronic heating systems.15 Common components of a central heating system using water-circulation include: A supply of fuel, electric power or district heating supply lines A Boiler (or a heat exchanger for district heating) which heats water in the system Pump to circulate the water Radiators which are wall-mounted panels through which the heated water passes in order to release heat into rooms. The circulating water systems use a closed loop; the same water is heated and then reheated.
Sealed systems offer an alternative to open-vent systems, in which steam can escape from the system, and gets replaced from the building's water supply via a feed and central storage system. Heating systems in the United Kingdom and in other parts of Europe commonly combine the needs of space heating with domestic hot-water heating.These systems occur less commonly in the USA.
In this case, the heated water in a sealed system flows through a heat exchanger in a hot-water tank or hot-water cylinder where it heats water from the regular potable water supply for use at hot-water taps or appliances such as washing machines or dishwashers.Źródło: https://en.wikipedia.org/wiki/Central_heating
A drain cleaner is a chemical-based consumer product that unblocks sewer pipes or helps to prevent the occurrence of clogged drains. The term may also refer to the individual who uses performs the activity with chemical drain cleaners or devices known as plumber's snake. Drain cleaners can be classified in two categories: chemical, or device. If a single sink, toilet, or tub or shower drain is clogged the first choice is normally a drain cleaner that can remove soft obstructions such as hair and grease clogs that can accumulate close to interior drain openings..
Chemical drain cleaners, plungers, handheld drain augers, air burst drain cleaners, and home remedy drain cleaners are intended for this purpose. If more than one plumbing fixture is clogged the first choice is normally a drain cleaner that can remove soft or hard obstructions along the entire length of the drain, from the drain opening through the main sewer drain to the lateral piping outside the building.Electric drain cleaners and sewer jetters are intended for this purpose. Each type of drain cleaner has advantages, disadvantages, and safety considerations as described below.Źródło: https://en.wikipedia.org/wiki/Drain_cleaner