idrive300

Hi there, first time hot tub owners. Just bought a 2019 Sundance Optima 880 used. Had it delivered this week and hooked up to power. Flipped the breaker and we got the error message "The flow switch is open. The heater is disabled. The circ pump's filter is dirty, or an air lock has occurred at the pump intake. Refer to owner's manual for additional information." Nothing comes on except the display. We cannot turn on lights, jets, or anything else. Have tried to purge any air out through draining out some water, and also using the garden hose to force water into the system to purge the air. But when we turn the breaker on nothing happens. We are pulling our hair out over here! Help!!