Details are given of the operation of a 90 deg annular sector of a ceramic-lined baffle-type combustor utilising premixed propane/air or propane/air/steam composition at ambient inlet conditions. Gas analyses are used to determine the combustion efficiencies, temperatures and compositions at a plane 8.9 in. downstream of the primary baffle. The results indicate the potential of the system for a low pollution chamber. They also show that most of the additional loss in efficiency, when steam is injected into the system, is due to increased hydrocarbon content.