The ECONOMY 7 QTZ is a Electric Water Heating Control, with high accuracy quartz clock movement, battery back up to maintain settings and an adjustable boost timer – the standard by which all other heating controls are judged. It supplied with its standard wall box and can be used to replace all previous Economy 7 Quartz models without needing any major re-wiring. It is suitable for use with cheap rate overnight tariffs such as Economy 7 or similar to provide a tank full of hot water each morning.