i have an older hot tub with a two speed pump, low works fine but high makes a nasty buzz/hum noise and blows breaker..
anyone know what this could be? thanks

Hi rich,

I think your pump should be have problem with the pump bearing and sometimes the bearing casing also.

When the pump running at low speed, would be no big deal but when the speed high should be make a noise and vibration. My suggestion you should service your pump or replace with new one.

Frank Wong
Hot Tubs & Spas

i dont think its the bearing. the buzzing sound is electrical, sounds like something shorting out, very loud... " title="Shocked" />

The noise comes from the motor and not your controls? Might be something as simple as a short in the wiring or as terminal as the high speed windings going bad. I'd open up the back plate (power off) and take a look to see if you notice any charring anywhere.