Is it okay to leave the flue open overnight?

Author: Vicente Ryan  |  Last update: Thursday, January 22, 2026

It's best to keep the flue closed when the fireplace is not in use. Should it stay open for too long cold air, debris, rain, and even animals can make their way inside your home.

Can you leave the flue open overnight?

Leave the flue open until everything is completely cold: overnight is probably best. More importantly, the embers are still combusting, and closing the flue while that's happening can deprive the embers of oxygen, leading to incomplete combustion and a buildup of carbon monoxide.

Will leaving the flue open make the house cold?

Closing the flue in your fireplace reduces the amount of warm air leaving your home; and thus you don't have the cold air coming through the vent in your bathroom. The chimney is fine, it's not leaking- but the draft of cold air is normal when you have an open flue straight up the chimney.

How do you put out a fire in a fireplace before bed?

  • 1. Fill a plastic spray bottle with water. Use a medium-size spray bottle as opposed to a cup or bucket to prevent splashing or excessive steam.
  • 2. Spread the firewood and embers in the fireplace with a fire poker.
  • 3. Spray the fire with water using the spray bottle.

Is it safe to leave a fireplace burning overnight?

Leaving a fireplace burning at night is generally not considered safe. Here are several reasons why: Fire Hazard: There is a risk of the fire spreading, especially if logs shift or if embers escape the fireplace. Carbon Monoxide: Burning wood produces carbon monoxide, which can be dangerous if it accumulates.

Leave Flue Open Overnight

Can a fireplace cause carbon monoxide poisoning while sleeping?

While it might be tempting to fall asleep near your gas fireplace on a chilly evening, it's actually putting your family at higher risk for carbon monoxide poisoning, fire, and smoke inhalation. A vent-free gas fireplace with easily accessible front doors shouldn't be operated more than three consecutive hours.

Is it okay to go to bed with embers in the fireplace?

Going to bed with embers in the fireplace presents significant safety concerns and potential risks. This includes the increased likelihood of a house fire due to unattended burning embers.

When to close a flue after a fire?

If the flue is left open after the fire goes out, all the heat generated will escape. Closing the flue will keep the heat inside; you must be careful not to close it too quickly, otherwise you may trap smoke and carbon monoxide in your home. It's best to keep the flue closed when the fireplace is not in use.

Can I sleep with my fireplace on?

While sleeping with a fireplace on can be comforting, it poses risks such as carbon monoxide exposure, ventilation issues, and fire hazards that need to be considered. Carbon monoxide exposure is a particularly concerning risk when it comes to sleeping with a fireplace on.

How do you keep a fireplace fire going all night?

Using smaller pieces of wood initially can help the fire build enough heat to sustain larger logs. Regularly adding wood and stoking the fire to maintain oxygen flow is essential. If your fireplace or stove has a vent, adjusting it to control airflow will also help keep a fire going.

Should the chimney flue be fully open?

The damper to your fireplace must be completely open when a fire is burning. If you close the damper even slightly, you risk allowing smoke and other dangerous contaminants from the combustion process into the house. And remember, the most dangerous by-product of combustion is carbon monoxide.

Can a flue catch fire?

"Flue fires are perennial". They happen every winter when creosote deposits on the smoke chamber and flue walls are set ablaze by high heat or by flames licking up the chimney. A chimney fire can be exciting and light up the night, but it is NEVER a laughing matter.

What is the difference between a flue and a damper?

The damper and flue are two different parts, but they are related and involved in the same function. The flue is the inside tunnel of your chimney that brings gases from your fireplace out of your home, while the damper closes or opens the access to the flue.

Why does my house smell like a campfire after using the fireplace?

It's not unusual for a fireplace to have some sort of smoky smell coming from it. But if you are noticing an intense smell coming from the fireplace, possibly accompanied with some smoke inside your house, your chimney could be partially blocked.

Should you close the flue in the summer?

The primary reason to close your fireplace's damper during summer is to protect it from humidity and any extreme weather events that are commonplace during this season. Closing the damper also prevents critters from getting in and setting up their homes, which can cause flue blockage, poor airflow, and foul odors.

How to tell if a fireplace is safe to use?

What to Look For Near a Chimney
  1. A bird's nest or different particles on the top cap of the chimney.
  2. Absence of bricks or mortar on or across the chimney.
  3. Tree branches near the chimney.
  4. Loose portions of the steel edging bridge the space between the chimney and the roof.
  5. White stains at the masonry.

Can I run my fireplace all night?

The biggest risk of leaving a gas fireplace burning all night would be a house fire or gas leak. A gas leak due to failing components would mean toxic and deadly fumes pouring into the house and this is why each family that owns a fireplace should have working smoke alarms and carbon monoxide detectors.

Is it safe to leave a fireplace heater on all night?

Fireplace safety tips can reduce the risk even further. Though, it is still best to avoid leaving it on all night. Not only is this because the fireplace can use a large amount of electricity, but it's also because of the potential fire hazard that it presents.

Why do fireplaces make you sleepy?

This drowsiness can be attributed to the soothing effects of the crackling flames and radiant heat, which create a tranquil ambiance promoting relaxation. Increased carbon monoxide levels near a fireplace can impair cognitive function and lead to fatigue.

Can you go to bed with embers in the fireplace?

No, you should never leave a fireplace burning overnight or unattended during the day.

How much heat is lost through an open chimney?

Warm air from your home naturally rises, and an open chimney provides an easy escape route. In fact, it's estimated that up to 30% of your home's heated air can be lost through an open chimney when the fire isn't in use.

Does closing the damper make the fire hotter?

Use the Damper to Control Heat

Depending on how far open or shut you have the damper, your fire will be smaller and cooler (and burn for longer), or larger and hotter (and burn more quickly). The damper is usually located at the bottom of the stove.

Can you leave a fireplace burning overnight?

No, leaving a wood-burning fireplace on overnight is unsafe. It poses risks of house fires, carbon monoxide poisoning, and chimney fires. Always extinguish the fire completely.

Is it bad to sleep next to a fireplace?

There is a risk of carbon monoxide poisoning when you sleep in a room where a conventional coal or gas fire, a log burner, a cooker, or a back burner is left on overnight. You cannot feel the early symptoms of carbon monoxide poisoning, so it is important that you protect yourself.

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