Diagnosis
The three-beep alert is a travel limit error. The opener thinks the door is already at its limit position. This often happens after a power outage or if the limits were recently set incorrectly.
How to Fix It
You need to reprogram the travel limits. First, pull the red emergency release cord to disconnect the door from the opener. Manually lift the door to a fully open position. Press and hold the 'Learn' button on the motor unit for 6 seconds until the LED turns solid amber. Then press and hold your wall button. The motor will run to set the open limit. Close the door manually to a fully closed position. Press and hold the wall button again to set the close limit. The light will flash green when done. Reconnect the door to the trolley.
If That Didn't Work
The limit switch assembly inside the motor unit could be faulty. This requires opening the case and checking the microswitches on the circuit board. A replacement logic board is the fix.
Heads Up
Never attempt to adjust the physical limit screws on the side of this model. The 3024 uses electronic limits only. Turning those screws can cause internal damage.