Microwave-assisted chemical recycling is envisioned as a promising strategy to recycle and valorise plastic residues in a cost-effective and energy-efficient way. The selective microwave heating provides a three-fold process intensification with respect to conventional heating technologies that rely on fossil fuels: a) electrification and, thus, possibility to use renewable energies to run the system, b) severe reduction of sample heating and cooling times, c) remarkable decrease of operational temperatures for a certain polymer valorisation degree. The chemical recycling requires, however, a very accurate temperature control to conduct the plastic depolymerization process properly and avoid undesired side reactions. In this frame, the purpose of the current work is to model and simulate the heating pattern of a one-litter polymer solution, i.e. polyamide 66, in a multimode MW-assisted reactor prototype and to validate the model with experimental temperature measurements, as a previous step for technology scaling.