A highly poisonous gas that has no colour, taste or smell. It can be produced by any appliances burning gas, wood, oil or coal, and can kill without warning in just a matter of hours.

A type of backflow preventer installed in a pipe run that allows water to flow in only one direction.

Rainwater storage tank, sometimes underground.

A valve for regulating the flow of water, sometimes referred to as a ballcock.

Boilers that heat water immediately, with no need for a hot water cylinder.

Building drain system vertical vent which connects two or more fixture branches on the same level.

A kind of tubing or pipe connection where a nut, and then a sleeve or ferrule is placed over a copper or plastic tube and is compressed tightly around the tube as the nut is tightened, forming a positive grip and seal without soldering. Also a flexible connector that has a nut and gasket designed to attach directly to an SAE standard compression thread, without the use of a sleeve or ferrule.

A type of valve that is often used for water faucets. It is opened or closed by raising or lowering a horizontal disk by a threaded stem.

A highly efficient boiler that extracts heat from flue gases instead of wasting. It can be up to 95% efficient, the remaining flue emissions being released as steam.