Each time the spa is powered up, it will enter Priming Mode. The purpose of Priming Mode is to allow the user to run each pump and manually verify that the pumps are primed (air is purged) and water is flowing. This typically requires observing the output of each pump separately and is generally not possible in normal operation.  



Priming Mode lasts 4 minutes, but you can exit it earlier by pressing any the Temperature Up or Down button. The heater is not allowed to run during Priming Mode.