How to Prime a Hot Tub Pump

Patrick Nelson

Hut tubs need to be primed in order to purge air. Air restricts the pump action. You can tell when a hot tub isn’t primed properly because the motor operates, but no water flows to the jets.

Purge the air in your hot tub pump.

There is usually no error message on the display because the motor, pump and other parts are, in fact, working fine, it’s just through laws of physics that the unpurged air is causing the jets not to work. You can prime your hot tub by purging the air yourself.

  1. Shut down the hot tub. Turn off the power at the wall. Look for a breaker box within a few yards of the hot tub if there isn’t an apparent hot tub circuit in the home’s principal circuit breaker set. Many codes require a switch near the hot tub. It will be in a weatherized box—usually gray.

  2. Take the handle off the massage selector that’s supplied by the pump you need to prime. Many hot tubs have more than one pump. You can tell which one needs priming because that’ll be the one that supplies the failed jets.

  3. Turn the massage selector’s cap counter-clockwise a little. Listen for seeping air. You should hear it hiss.

  4. Turn the massage selector cap clockwise to tighten it when the hissing stops. Turn it finger tight. The hot tub pump is now primed. Turn on the hot tub and test. Repeat Steps 1 to 4 with any other problem jets.