CaCO3 deposition on surfaces in heat exchangers is a serious problem across several types of industries, and there are many numerical models across the literature that attempt to understand and predict its behavior. In this work, we present a break-off model that considers both the aging of the CaCO3 and the temperature distribution in the layer. By doing so, we allow for layers of the fouling material to break due to thermal stress. Our results show this model agrees with experimental data better than previous models, and it explains the breaking behavior usually found in such data. (C) 2017 Elsevier Ltd. All rights reserved.