Unclogging the Lines
Squirt a small amount of liquid dish soap into the clogged line to lubricate it, making removing the blockage more easy.
Press a sink plunger over the clogged line and plunge it several times to remove the obstruction from the line. If the line remains clogged, go to the next step.
Remove the jet nozzle with pliers then insert a small pipe auger into the line. Crack the handle to push the blockage out of the line. Once clear, replace the jet nozzle.
Fixing the Tub Pump
Turn the Whirlpool bath off and power off the pump as well. Let the pump cool to room temperature if recently used.
Remove the Whirlpool's pump cover using a screwdriver and pliers. Locate the motor and impeller assembly inside the pump housing. The impeller assembly looks like a shaft with small propeller blades.
Examine the impeller assembly to see if something is blocking it, making the pump stick. If the blades are damaged, remove the impeller assembly and replace it.
Check the motor to ensure it is working using a voltage reader. Connect a voltage reader to the Whirlpool tub pump motor and take a reading. If it is bad, that is the source of the problem. Remove and replace the motor.
Replace the pump cover after making the necessary repairs. Turn the power back on and use your Whirlpool bath as normal.