How can you tell a banger is past it's life?

Hey fellow tokers. I've been dabbing for a bit now but one thing I can never tell is when my banger is past it's life.

The reason I ask is because my current banger gets red hot and will cool down to temp in about 20 to 25 seconds but will always leave a puddle even if I take the dab way too hot. I use a directional flow carb cap and have never had this issue with any bangers before. It's a bit cloudy but not black.

Thanks