Hot tub spa pumps do most of the work in the tub's plumbing. A faulty pump will often result in restricted water flow and reduce the output of jets inside the hot tub. Pumps can have a variety of issues, which will require you to follow some steps for troubleshooting.
Pumps that do not work may need you to reset power to the spa. You can either press the "reset" button at the GFCI or turn off power at the breaker. After you turn power back on, the pump will re-prime, attempting to correct any problems.
Low water inside the hot tub or an extremely dirty filter can limit the amount of water the pump draws from the tub. This will cause the pump to work improperly and possibly not at all. Clogged intakes inside the tub can also cause pump problems.
Noisy, humming or excessive vibration can indicate major pump problems. You can open the access panel to ensure all pump valves are open and no issues exist with the plumbing. Replacing the pump may require a service call from the dealer.