I’m in the process of refinishing my basement, and I’ve installed the breakers. My panel uses Square D QO breakers that have a window that shows red when the breaker is in the tripped position. Breakers are then reset by turning fully off and then on.
One of the new breakers shows just a tiny bit of red in the window when it’s in the “on” position. It doesn’t instantly trip when turned on. It does this even with the breaker removed from the panel. The breaker switch moves fully to both on and off positions.
Is this something to be concerned about?
It is absolutely just more cost effective, safer and better piece of mind to just replace the breaker. I'll take that route 99.99% of the time.
If you feel adventurous, there are a couple of ways to test that breaker without proper test equipment. The risks could be zero OR you blow your face off and burn your house down.
Find an open outlet at tap live to ground. This will produce some natural and organic indoor fireworks, but it should trip the breaker. If it doesn't, there is a small risk of welding the wires together and creating a very strange short condition, turning that entire circuit into a new heat strip. (Free money!)
Find two 1800W space heaters and together, on the same circuit, they should trip the breaker as well. (Breakers should be rated to at least 1800W.) This is problematic as well and I'll explain. There is something magical about space heaters as I have seen 2 or 3 run off of the same circuit before. I suspect that if a breaker is slowly warmed up due to heavy load it will change its characteristics, causing it to only trip at higher loads. (Absolute speculation on my part!) By default, I would replace the breaker if I saw that kind of load. Extended, and higer heat cycles will eventually damage the breaker.