End turn insulation failures and bearing failures are the primary modes of failure in BLDC motors. Bearings are a matter of initial quality and environment, but the end turns are where the windings in a BLDC are least supported and where the insulation is subject to the greatest stress as a matter of construction.
In contrast ECM machines have windings that are completely constrained and encapsulated, including the end-turns. These end-turns experience no insulation stress as a matter of construction. In the event that an ECM machine stator does fail, it is a single component that can be replaced.
