The (I^2R) heat losses in a transformer are caused by the primary and secondary winding resistances, as the page below lists the transformer losses:
But what about the eddy currents don't they generate resistive losses?
I found the following:
Eddy current loss is conductive I2R loss produced by circulating currents induced in response to AC flux linkage, flowing against the internal resistance of the core. So, based on the above is eddy current loss a heat loss?
SOURCES:
The Principles and Practice of Engineering (PE) Electrical and Computer: Power exam Reference Handbook Version 1.1.1 Pub. NCEES