Hi P-nut
Welcome to the forum.
If the faceplate is good, meaning no cracks above the temperature controller, you will only need to replace the circuit board. If the faceplate is cracked then I recommend replacing both. You can purchase replacement parts from
Yard & Pool.
The indicator light is connected to the heat controller, and the lower you set the temperature the dimmer the light will glow, and in daylight it is difficult to see if it is working properly. The light will be the brightness when the temperature switch is all the way to the right. Some members say you shouldn't go all the way to the right, because there is a dead spot, so then back off a hair. So if your heating element is working properly, you may not need to replace the temperature controller.
The below link is a good source for trouble shooting and tips:
Bradley FAQ's