The most common issue that creates a FLT03 on the Ax60+ is that there is a communications fault between the sensing element and the sensor unit, likely due to the black sensor wires being damaged when closing the enclosure lid. To resolve this issue it is advised to power cycle the device first. If the fault occurs still, then open the relevant sensor unit and check that the sensing unit is correctly plugged in and no wires and damaged or sticking out.
In the case of wire/wires sticking out of the relevant connectors, then simply turn off the system (making sure the wires are no longer live) and unscrew the wire/wires making sure that they are when screwing them back into the connector that no metal is out.
However, if the wire/wires are damaged or there seems to be nothing wrong with the wires, then its a case of recalling the sensor unit back to Analox where it will be returned and fixed with our engineers.