The only thing that should cause an alarm is the float being raised, it can also sound for too low but only if this was turned on in the past. The manual explains how to turn off the alarm on page 48-49. If the alarm is coming on without the float being raised the most likely cause is magnetic interference, generally the float wire is bundled to another wire and transfering interference, the two sensor wires can be tied together but should never be bundled to any other wires.