Common Candle Problems and How to Fix Them

Even the best candles can develop problems if not cared for properly, and sometimes manufacturing defects occur. As a professional candle maker, I've seen every issue imaginable—and fixed most of them. This comprehensive troubleshooting guide will help you identify what's going wrong with your candles and, in many cases, rescue them. Understanding these common problems will also help you prevent them from occurring in the first place.

Tunneling

Tunneling is the most common and frustrating candle problem. It occurs when a candle burns straight down the centre, leaving a thick rim of unmelted wax around the edges.

What Causes Tunneling

• Insufficient first burn: Not allowing the melt pool to reach the container edges during initial burning
• Short burn sessions: Consistently extinguishing the candle before a full melt pool forms
• Wick too small: Manufacturing defect where the wick can't generate enough heat
• Draughty locations: Air currents cooling one side faster than another

How to Fix Tunneling

1. Extended burn session: Burn the candle for 4 hours (maximum safe time) and see if the melt pool catches up to the edges. Repeat if necessary.
2. Foil tent method: Create a tent of aluminium foil over the candle (with a hole at the top for airflow), which reflects heat inward and helps melt the outer wax. Monitor constantly for safety.
3. Hair dryer method: Use a hair dryer on low heat to melt the top surface evenly, then light normally.
4. Candle warmer: Place the candle on a warming plate to melt all the surface wax, then burn as usual.

Sooting and Black Smoke

Soot appears as black marks on the container or nearby walls. Excessive smoke indicates incomplete combustion.

What Causes Sooting

• Untrimmed wick: The most common cause—long wicks produce larger, unstable flames
• Draughts: Air currents cause the flame to flicker and burn unevenly
• Burning too long: Sessions over 4 hours cause carbon build-up on wicks
• Poor quality wax or fragrance: Some formulations produce more soot than others
• Container too narrow: Insufficient oxygen reaches the flame

How to Fix Sooting

1. Extinguish the candle and let it cool completely
2. Trim the wick to 5mm, removing the "mushroom" carbon cap
3. Clean soot from the container with a dry paper towel or rubbing alcohol
4. Move the candle away from draughts and air vents
5. Burn for shorter periods (under 4 hours)

Weak or No Scent Throw

When your candle doesn't seem to release much fragrance, it's disappointing—especially with premium candles.

What Causes Weak Scent

• Cold throw vs. hot throw: Some candles smell stronger unlit than burning, and vice versa
• Room size: A small candle can't fragrance a large room
• Olfactory fatigue: Your nose has become desensitised to the scent
• Low fragrance load: Cheap candles may have minimal fragrance oil
• Aged fragrance: Scent can fade over time, especially in old or improperly stored candles
• Competing smells: Cooking, cleaning products, or other fragrances overpower the candle

Solutions for Weak Scent

• Allow a full melt pool: The larger the liquid wax area, the more fragrance releases
• Close doors: Contain the fragrance in a smaller space
• Step out and return: Leave the room for 15 minutes, then return to reassess
• Use appropriately sized candles: Match candle size to room size
• Try multiple candles: In very large rooms, burn 2-3 candles
• Switch scents regularly: Prevent olfactory fatigue by rotating fragrances

Wick Problems

Drowning Wick

When the wick becomes submerged in melted wax and won't stay lit, you have a drowning wick.

Causes: Too much wax melted at once, often from burning too long, or a wick that's too short.

Solutions:

• Pour off some melted wax onto a protected surface (carefully!)
• Use a paper towel to absorb excess liquid wax around the wick
• Let the candle cool, then dig out some wax around the wick
• Use a toothpick to lift the wick and hold it upright while wax solidifies

Mushrooming

When the wick develops a ball or "mushroom" shape at the tip, it causes larger flames and more soot.

Off-Centre Wick

When the wick is positioned too close to one side of the container, that side overheats while the opposite side doesn't melt properly.

Solutions:

• While the wax is melted, gently guide the wick back to centre using a stick or skewer
• Rotate the candle 180 degrees periodically to even out burning
• If severely off-centre from purchase, contact the manufacturer

Wet Spots and Frosting

These cosmetic issues don't affect performance but can be visually disappointing.

Wet Spots

Areas where the wax has pulled away from the glass, creating a patchy appearance.

Causes: Temperature fluctuations during cooling or storage. This is particularly common with soy wax.

Reality check: Wet spots are purely cosmetic and don't affect burn quality or scent throw. They're a natural characteristic of soy wax and indicate a natural product.

Frosting

White crystalline patterns on the wax surface, especially common in soy candles.

What it means: Frosting is actually a sign of natural soy wax! It's caused by polymorphism—the natural crystalline structure of vegetable wax. It doesn't affect performance and many consider it a hallmark of quality natural candles.

Flame Issues

Flame Too High

A flame taller than 3cm is too large and creates safety concerns.

• Extinguish immediately
• Let cool and trim wick to 5mm
• Move away from draughts
• If problem persists, the wick may be too thick (manufacturing issue)

Flame Too Small or Goes Out

A weak flame that barely stays lit or extinguishes itself.

• Trim away any debris in the wax pool
• Pour off excess melted wax if the wick is drowning
• Check for draughts that might be blowing out the flame
• The wick may be too small (manufacturing issue)

Flickering Flame

Constant flickering, not just occasional movement.

• Move away from air currents (windows, vents, foot traffic)
• Trim wick if it's too long
• Check for debris in the wax pool

Container Issues

Overheating Glass

If a glass container feels dangerously hot, especially at the bottom:

• Stop burning when 1cm of wax remains at the bottom
• Always use a heat-safe surface under candles
• Don't burn for more than 4 hours at a time
• If the container seems to overheat prematurely, stop using it

Cracked Container

Cracks can occur from thermal shock or defects. Stop using cracked containers immediately—they're a fire and hot wax hazard.

When to Give Up

Sometimes a candle is beyond saving due to manufacturing defects:

• Severely off-centre wick that can't be corrected
• Wick that repeatedly drowns or won't stay lit
• Strong chemical or unpleasant smell when burning
• Cracked or damaged container
• Persistent smoking despite all troubleshooting

Contact the retailer or manufacturer for defective products. Reputable brands will often replace problematic candles.

Conclusion

Most candle problems are preventable with proper care—particularly wick trimming and appropriate burn times. When issues do arise, they're often fixable with the techniques described above. Understanding what causes these problems empowers you to prevent them and enjoy your candles to their fullest potential. Keep this guide handy for troubleshooting, and remember that a little maintenance goes a long way in candle care.