A heated gas generation system for generating heated gas from waste product, the system comprising: a gasifier which includes a primary chamber for receiving waste product and including at least one air inlet and at least one gas outlet, a burner for igniting waste product held in the primary chamber, and an air delivery unit for delivering air into the primary chamber through the at least one air inlet of the primary chamber; and a combustor which includes a secondary chamber including at least one gas inlet which is fluidly connected to the at least one gas outlet of the primary chamber, at least one air inlet and at least one gas outlet, at least one burner for preheating the secondary chamber, and an air delivery unit for delivering air through the at least one air inlet of the combustor; characterized in that: the gasifier is controlled, in a first mode of operation, by regulating delivery of air to the primary chamber so as to heat the waste product to extract syngas or synthetic gas from the waste product and deliver a stream of syngas through the at least one gas outlet of the gasifier, and subsequently, in a second mode of operation, following extraction of syngas from the waste product, by regulating delivery of air to the primary chamber to be greater than delivery of air to the primary chamber in the first mode of operation of the gasifier so as to burn the waste product to provide a stream of heated gas and deliver the stream of heated gas through the at least one gas outlet of the gasifier; and the combustor is controlled, in a first mode of operation, by regulating delivery of air to the secondary chamber so as to maintain the secondary chamber at a temperature of at least 850 °C and burn the stream of syngas which is delivered from the primary chamber in the first mode of operation of the gasifier to generate a stream of heated gas through the at least one gas outlet of the combustor, and, in a second mode of operation, deliver the stream of heated gas which is delivered from the primary chamber in the second mode of operation of the gasifier through the at least one gas outlet of the combustor. a gasifier which includes a primary chamber for receiving waste product and including at least one air inlet and at least one gas outlet, a burner for igniting waste product held in the primary chamber, and an air delivery unit for delivering air into the primary chamber through the at least one air inlet of the primary chamber; and a combustor which includes a secondary chamber including at least one gas inlet which is fluidly connected to the at least one gas outlet of the primary chamber, at least one air inlet and at least one gas outlet, at least one burner for preheating the secondary chamber, and an air delivery unit for delivering air through the at least one air inlet of the combustor; characterized in that: the gasifier is controlled, in a first mode of operation, by regulating delivery of air to the primary chamber so as to heat the waste product to extract syngas or synthetic gas from the waste product and deliver a stream of syngas through the at least one gas outlet of the gasifier, and subsequently, in a second mode of operation, following extraction of syngas from the waste product, by regulating delivery of air to the primary chamber to be greater than delivery of air to the primary chamber in the first mode of operation of the gasifier so as to burn the waste product to provide a stream of heated gas and deliver the stream of heated gas through the at least one gas outlet of the gasifier; and the combustor is controlled, in a first mode of operation, by regulating delivery of air to the secondary chamber so as to maintain the secondary chamber at a temperature of at least 850 °C and burn the stream of syngas which is delivered from the primary chamber in the first mode of operation of the gasifier to generate a stream of heated gas through the at least one gas outlet of the combustor, and, in a second mode of operation, deliver the stream of heated gas which is delivered from the primary chamber in the second mode of operation of the gasifier through the at least one gas outlet of the combustor. the gasifier is controlled, in a first mode of operation, by regulating delivery of air to the primary chamber so as to heat the waste product to extract syngas or synthetic gas from the waste product and deliver a stream of syngas through the at least one gas outlet of the gasifier, and subsequently, in a second mode of operation, following extraction of syngas from the waste product, by regulating delivery of air to the primary chamber to be greater than delivery of air to the primary chamber in the first mode of operation of the gasifier so as to burn the waste product to provide a stream of heated gas and deliver the stream of heated gas through the at least one gas outlet of the gasifier; and the combustor is controlled, in a first mode of operation, by regulating delivery of air to the secondary chamber so as to maintain the secondary chamber at a temperature of at least 850 °C and burn the stream of syngas which is delivered from the primary chamber in the first mode of operation of the gasifier to generate a stream of heated gas through the at least one gas outlet of the combustor, and, in a second mode of operation, deliver the stream of heated gas which is delivered from the primary chamber in the second mode of operation of the gasifier through the at least one gas outlet of the combustor.