Firstly, take a quick look at our warnings and instructions on the base of the candle and inside the box. Always burn for a minimum of 1 hour to prevent tunnelling . Do not burn for longer than 2 hours. Before re-lighting always trim the wicks to 5mm and ensure they are upright. Trimming wicks reduces smoking and mushrooming . Lastly, never use the lid or water to extinguish your candle and always extinguish your candle when there is 10mm left at the bottom of the jar.