@Peakie 

Hi,

If the Powerline LED turns off at certain times during the day, but is on at other times, then this could be caused by some electric appliance or device in your home. (like phone charger, TV, microwave oven, etc.)

If the Powerline LED is always off, then you will probably need to decrease the distance between the two TL-PA4020P Powerline adapters.

As a test plug both TL-PA4020P into wall sockets located within the same room and see if the Powerline LED turns on.