I have a five year old pool, with a Hayward Tristar two speed pump. The pump runs fine on high speed, but when I put on low speed, it starts making a terrible humming noise and will shut off. It appears the pump is pushing water out of the return lines while this terrible humming happens, but, it appears the thermal overload protector is kicking in and shutting the pump off after a minute or so. I then shut the filter off and notice that high and/or low speed will not work(motor cooling off I suppose) and wait a bit and I can hear it 'reset' and the pump will fire back up just fine in high speed, and will make the terrible noise on low speed and eventually shut off. Do you think this is a capacitor issue?
Thanks in advance for any help...Jason