The air handler is a Bryant. The motors have been a General Electric X13 (the original patent-holder for the X13 electronically commutated constant-torque PWM m

The air handler is a Bryant. The motors have been a General Electric X13 (the original patent-holder for the X13 electronically commutated constant-torque PWM motor controller), a Regal Beloit "Evergreen" X13 OEM replacement, and now a Nidec X13 motor. These motors are microcontroller-based. Apparently there was a rash of bad GE X13 motors in the early 2000's traced to bad thermistors. Unfortunately the board is potted in an insulating compound that makes board-level repair rather impractical. My first motor's controller failed after about 8 years. It was cheaper to just buy a new motor vs. replacing only the controller. The second motor's rotor started grinding against the stator after about 13 months. I pulled the controller from that motor and installed it on the first motor (since it was near-perfect duplicate of the original motor). That ran for 14 months before the second controller failed. I've been running the third (Nidec) motor for about 2 months. I'll be interested to see how to holds up long-term.