On most spas you just push the pump btn
press once for low speed, press again for high speed, once more it shuts off. If you don't have a circulating pump, small pump that runs 24/7 then pump one will run on low speed when the unit is calling for heat. If you have your spa set to 104, the pump will run more often to maintain that temp. If you drop the temp down to say 80 then it should shut off. If you just filled it, the pump should run till the desired temp is reached then shut off. Is that what its doing??
