This is what most people ring about, so here's the straight answer.
What's usually wrong. A fan that won't start, or stops on its own, is most often a failed capacitor. Grinding or buzzing is worn bearings or a blade catching. Wobble is blades out of balance or mounting that's worked loose. Stuck on one speed is the speed switch.
Worth repairing. All of the above. Small jobs, and they'll buy you years more out of the fan. Under about ten years old with one fault, fix it. Glenn carries common capacitors, so plenty get sorted the same visit.
Worth replacing. Motor failure, corrosion through the housing, damaged mounting, or three things wrong at once. Past fifteen-odd years you're paying to patch a fan that's about to fail somewhere else.
The other reason people replace a working fan is the motor. An old AC motor pulls 50 to 75 watts, a DC motor pulls 10 to 40 and runs quieter.





