Here are some steps you can follow to fix a candle wick:

1. Wrap foil around the top edges of your candle while it’s lit. Burn your candle until the wax melts to the edges of the container. Heat the top layer of wax with a hair dryer to fix minor tunneling. Put your candle in the oven at 175 °F (79 °C) for 5 minutes to help melt the wax. Cut away the excess wax above the wick with a butter knife.
2. Melt the surrounding wax by using a heat gun or blow dryer. Dig out the wick. Light it.
3. Make sure that your wicks are long enough. Check the diameter of the wick carefully. Make sure that your wicks aren’t too damp. Clean your wicks and your candle holders. Let them dry out if necessary. Trim your wick to the appropriate length. Understand how to blow out your candles.
4. Re-wick the candle by either adding or inserting a new wick into the wax or creating a substitute wick to help the candle burn evenly to create a full wax pool. Alternatively, scrape out or melt the wax from around the wick.