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Agglomeration in fluidized bed combustion can be a big operational problem, leading to unwanted defluidization and shutdown of the installation. Therefore, the onset of such events has to be reliably detected in an early stage and combined with counteractions to avoid further agglomeration and defluidization. The suitability of the attractor comparison method to detect agglomeration in combination with different counteraction strategies is investigated on a laboratory-scale (∼1 kWth) and a small commercial-scale (∼1 MWth) fluidized bed combustor. The agglomeration characteristics and the time until defluidization occurs can vary considerably depending on scale and process conditions, but also for similar operating conditions on the same scale. In all cases, attractor comparison has shown to detect the approach of defluidization early enough to prevent defluidization if a suitable counteraction strategy is applied. A temporary increase of fluidization velocity to promote agglomerate break-up is not a useful method to avoid agglomeration on laboratory-scale. A decrease in operating temperature below the melting points of potassium silicates can be a successful emergency strategy to ensure continued trouble-free operation. However, a subsequent temperature increase leads to further agglomeration, potentially very rapid, with alkali still present in the bed; therefore, some strategy to replace the bed content or neutralize the alkali is necessary. Semicontinuous replacement of bed material is shown to be a successful permanent solution to avoid defluidization. Yet, its application requires careful economic consideration. For larger reactor scales, agglomeration can occur more localized, which justifies several measuring positions. Especially for monitoring transition regions, for example, start-up, the application of a moving reference that has a constant negative time offset to the evaluation window is advantageous.