When you turn a pump on and it doesn't do anything it could mean a couple different things...
1. Is there power going to the pump? Check the breaker! Has it been tripped? Do you need to trip it and turn it back on? Make sure you FULLY flip it off and FULLY flip it back on. There is sometimes a halfway point in breakers that you have to get past.
2. Is the capacitor bad? The capacitor is the battery looking thing in the back of the motor and is what jumpstarts the motor. You can usually tell if the capacitor needs to be replaced by manually spinning the shaft of the motor. If it spins freely/ feels loose, then the capacitor is probably bad. Replacing it is very easy! Turn power off, take the leads off the old capacitor and put them on the new one. Put the leads on seperate prongs. You can manually jump start the motor in this position by turning it on and spinning the shaft yourself.
3. If you take off the cap of the motor and the shaft will not spin, the bearings inside are siezed and its best to just replace the motor. The fastest turn around time is to bring the motor in to our store! Disconnect power to the pump, and take the bolts off the seal plate to disconnect the motor from the pump. Leave the difusser and impeller connected and we will take care of the rest.
4. If the pump comes on but then kicks off randomly it could be hitting the thermal overload. Feel the back of the motor when this happens. If its scolding hot, you probably need to replace the motor. They wont run if they get too hot and the older they get the hotter they run.