Is it possible the TM5 could have trouble heating food if it is overloaded with a lot of ingredients or frozen ingredients? Yes. Colder and larger quantities of food may require more time to heat. Related articles Thermomix® sells mixing bowls in many countries around the world. Does a non US mixing bowl work in the US version of the TM5? What if a TM5 does not heat food quickly or at all? How can I update the software on my Thermomix ® TM5? Is there a "How to" video on Cookidoo and the Cook-key? What if the mixing knife (blade set) is not working properly in a TM5? It is possible to hear the Thermomix® motor moving but the mixing knife is not moving.