What is commonly referred to as a hot tub “pump” actually consists of two parts. The motor is the metal part, and the pump is the plastic “wet end” part. The metal shaft of the motor is what turns the plastic impeller (pump) encased in the “wet end” assembly.
-Check to see if the motors look new or worn & rusted
-Check to make sure the main pump (referred to as “pump #1) has two speeds and make sure the other pump(s) are working as they should.
-Activate the pump(s) for several minutes then feel the motor bodies with your hand. If it feels hot to the touch, it may be overheating.
-Check the shaft (the metal rod between the motor and wet end) for rust, corrosion or wetness/leaking (this indicates the seal is failing)
-If the motor sounds loud, the bearings are likely failing.
-If the wet end is lend is loud and vibrating, the impeller might be damaged.