A coil that tastes burnt is predominantly down to the fact that the cotton within the coil has either become burnt somewhere or is entirely burnt. This burning taste is an indication to the user that they need to replace the coil within their tank or pod of their vape kit for a new one.
Please ensure that with all brand-new coils that you prime your new coil by placing a drop of e-liquid on each cotton hole on the sides of the coils and then leave it in a tank or pod full of e-liquid for 10-15 minutes before using. This enables the cotton on the inside of the coil to saturate with e-liquid and avoid prematurely burning it out.