Question: how do you know when to change coil on vape?
Answer: Your Vape Tastes Burnt. This is probably the most noticeable thing that tells you your coil needs replacing, and something most vapers will experience. ... 
Your E-Cigarette Is Gurgling. ... 
Your Vape Tastes 'Strange' ... 
Your Coil Is Used Up. ... 
E-Cigarette Leaks.