8811 - Máy soi chiếu phóng xạ phương tiện và đường sắt luôn báo hiện diện liên tục

Take care that you replace the barrel sensor with the appropriate spare. Black with black, yellow with yellow, and verify the label indicates that it is a receiver or transmitter, and that model numbers match.

It would be extremely unlikely for both IR Occupancy sensor pairs to be faulty at the same time. Recheck the sensor functionality and wiring carefully before deciding to replace IR occupancy sensors.