Flue boilers

are usually single shells containing a small number of large flues, through which the heat either passes from the fire or returns to the chimney, and sometimes containing a fire box inclosed by water.

See also: Boiler

References in periodicals archive ?
Replacing open flue boilers with more energy efficient models, Corgi claims, could reduce the UK's carbon footprint by almost 1%, cut domestic gas bills by 24% and also help reduce the risk of carbon monoxide poisoning.