Carpet Pro Thermal Reset - CPU1/CPU1T Upright

The thermal reset is the protective switch that cuts power to the motor when it runs too hot, and this is the replacement, part B333-0400B. It covers a wide slice of the commercial range: Carpet Pro CPU1QD, CPU2, CPU3N, CPU3QD, CPU4N, CPU4T and the CMP3 series, Clean Max CMPSQD, Fuller Brush FBHD1, FBHD1T, FBMMPWCF4, FBP14PW, FBPHD2, FBPHD2T and FBP-14PWBP, Maytag M700, Powr-Flite BP6S, BP6P, BP10S and BP10P, and Titan T4000.2, TC6000 and TC6000.2.

The classic symptom is a machine that dies partway through a job and runs again after twenty minutes on the floor. Sometimes the motor really is overheating, from a clogged filter, a full bag or a jammed brush roll — check those first. When airflow is clear and it still trips, the reset itself has become oversensitive and is cutting out early.