Abstract: The present invention provides a heating appliance which comprises a combustion chamber, a boiler adjacent the combustion chamber, and a flue system for conveying combustion gases from the combustion chamber. The flue system has two different routes for conveying combustion gases and a damper which may be selectively positioned to cause the gases to pass predominantly along either one or the other route. This arrangement permits the heat output to the boiler and an associated cooker unit to be varied while a constant firing rate is maintained in the combustion chamber. The applicance is preferably operated on solid fuel.