Solid fuel combustion appliance

A solid fuel combustion appliance comprises a primary combustion chamber 16, and a secondary combustion chamber 14 arranged at the rear of the primary chamber. The secondary combustion chamber has a downwardly opening inlet 15 to receive combustion products from the primary combustion chamber leading upwardly into a first passageway 17 and an outlet disposed adjacent the bottom of at least one second passageway 23 disposed rearwardly of the first passageway, and means 30 to 33 for supplying preheated air into the secondary combustion chamber, and the outlet of the second passageway communicates with an upwardly extending flueway (not shown) laterally adjacent the passageway 23. Both the top of the first passageway 17 and the top of the flueway have respective openings for the emission of combustion products from the appliance, and the appliance further comprises a slidable damper 29 for selectively opening and closing the top of the first passageway whereby when the top of the first passageway is open at least the greater part of the combustion products entering the inlet from the primary combustion chamber pass upwardly in the first passageway for emission directly from the open top thereof, whereas when the top of the first passageway is closed at least the greater part of the combustion products entering the inlet initially rise upwardly in the first passageway, subsequently change direction within the secondary combustion chamber to pass downwardly in the second passageway to the said outlet, and finally pass upwardly in the flueway for emission from the top thereof.