How to Water Test a Spa Pump

Power off your hot tub and locate the equipment compartment on the side of the tub.

Remove any screws holding the compartment cover in place. Remove the compartment cover. The spa pump will now be visible. It is about the size of a football and there will be piping and valves connected to it.

Power on your hot tub and turn on the jets to perform the test. The pump will then activate.

Listen to the pump. If you can't hear anything at all but there is power to the spa motor, then there is likely an electrical problem and you will need to call a professional to avoid damaging the machinery. If the pump hums and vibrates, but doesn't push water, proceed to the next step.

Shut off the power to the spa and unscrew one of the plumbing unions attached to the pump. The plumbing unions are large nuts or bolts that attach the piping to the motor. Loosening and unscrewing the union will release any air that has built up in the spa. Too much air in the pump may cause the spa to shut down.

Replace the plumbing union by screwing it back into place.

Inspect the pump for signs of corrosion or damage, such as rust, leaks or bursted piping. This could also be a reason your spa isn't functioning properly. If the pump is heavily corroded, you will likely have to replace the pump.