Hot gas test beds are important tools for developing and testing turbochargers. In such a unit the turbine is fed by a combustion chamber. Hot gas temperature and mass flow rate are important quantities during testing. However, the use of PI-control often leads to unsatisfactory temperature control performance. This article presents a new model-based temperature control strategy. The new model is obtained by modifying an existing thermal model of a biomass furnace. To estimate the unknown model state a Kalman-Filter is used. Measurements on the test bed prove better reference tracking as well as disturbance rejection.