Fireplaces offer a cozy ambiance to any room, but the fear of a fireplace getting too hot is a real concern for many homeowners. It is important to understand fireplace safety and the possible consequences of what can happen if a fireplace overheats.
Fireplaces can often get too hot because of ventilation issues or if too much fuel has been added to them. Fireplaces are designed to handle heat up to a certain point. However, adding too much fuel, albeit gas or wood, to your fireplace will cause it to overheat and damage it.
So how do you know if you’re overheating your fireplace? In this blog post, we’ll go over the signs of an overheating fireplace and how you can safely cool it down. We’ll also touch on how to prevent your fireplace from overheating in the first place.
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Here’s a Quick Pro Tip!
Overheating your wood-burning or gas fireplace can damage your fireplace or even the walls and area around the fireplace. You should know the fuel limit (gas or wood) for your fireplace model.
Our top picks to control the heat from your fireplace:
1. Mantel heat deflector – Ideal if you find your mantel feeling excessively hot.
2. Fireplace blower/fan – Perfect for increasing the efficiency of your fireplace.
3. Fireplace poker – Ideal for moving hot embers to dampen the fire.
Is It Possible For a Fireplace to Overheat
It sounds contradictory, right? How can you overheat something that is meant to produce heat? Well, actually, it’s quite easy to overheat your fireplace.
We’ll discuss what that means exactly and what you might be doing wrong.
Can You Overheat a Fireplace?
You can overheat a wood-burning fireplace by filling it up to the brink with wood. The fireplace is not designed to handle that amount of heat, and doing this can actually be extremely damaging to your fireplace.
Wood-burning fireplaces and stoves are designed to work at a certain temperature.
Overheating can lead to unsafe temperatures inside your fireplace, chimney, and flue or even warp your entire fireplace.
How Much Heat Can a Fireplace Handle?
Generally, a wood-burning fireplace can generate temperatures around 1500°F. Although, a wood-burning fireplace loses a lot of heat through the chimney or flue. These fireplaces can produce between 20000 and 40000 BTUs (British Thermal Unit).
BTU is used to measure energy, more specifically, 1 BTU refers to the amount of energy that’s required to increase the temperature of a pound of water by 1°F. This unit of measurement is mostly used when measuring air conditioners or heating units.
A gas fireplace can emit anything between 7000 and 60000 BTUs. Thus, it’s much more energy-efficient than traditional wood-burning fireplaces. Thankfully, they can be easily added to a house if you want to swap out your wood-burning fireplace.
Luckily, modern wood-burning fireplaces are also much more energy efficient.
You might also enjoy our post on If You Can Leave a Fireplace Burning Overnight
How Do I Know if My Fireplace Is Too Hot?
If you have a traditional wood-burning fireplace, inspect the exterior and interior of your fireplace. If you see heat damage, like melting or scorching, it’s safe to assume that your fireplace has been running too hot.
Your chimney could also overheat and ultimately crack due to not being able to handle the amount of heat it is being exposed to.
If the tiles or bricks around your fireplace feel hot to the touch, that could also be a sign that your fireplace is too hot.
What Does Over Firing Look Like?
When the glass stays black for a longer period of time, that means your wood stove is over-firing. Another sign is noticing creosote build-up on your chimney flue pipe, or hearing popping sounds in your firebox.
Noticing any one of these signs should prompt you to call in a professional to have a look at the condition of your fireplace and chimney.
In the meantime, you could turn down the air intake and reduce the temperature of your fireplace.
What Is Over-Firing a Fireplace?
Over-firing your fireplace means burning your fuel too hot and going above the recommended temperature designated by the manufacturers of the fireplace. This ultimately leads to heat damage to the fireplace and chimney.
People tend to pack the fireplace full of wood if they’re getting cold, but it’s not designed to burn that much wood at once.
Overfiring can also cause you to feel physically uncomfortable from how hot your room is. A fireplace should only make the room cozy, not hot.
Is It Normal for Fireplace Surround to Get Hot?
The wall area surrounding your fireplace will get quite hot, and this is normal. Although, it should not be too hot for you to touch. That is an indication that something might be wrong, and you need to contact a professional.
A general rule of thumb is that the surrounding wall should not be hotter than 100°F, or if you suddenly realize your wall feels a lot hotter than usual.
These are indications to call a local carpenter to check out your fireplace.
Why Does the Wall Above My Gas Fireplace Get Hot?
Gas fireplaces do not burn as hot as wood-burning fireplaces, so the walls surrounding your gas fireplace should not really get hot. It might be a little warm, but if you notice excessive heat, there might be a problem.
A gas fireplace creates carbon monoxide, carbon dioxide, and other toxic gasses. These gasses escape the fireplace along with the heat and seep into the air of your home.
Additionally, you might notice heat damage to tiles on your wall.
Is It Okay if My Heat and Glo Fireplace Is Too Hot?
A fireplace that is too hot should never be ignored. The excessive heat could cause damage to your floors, walls, and even the fireplace itself. If you have a gas Heat & Glo fireplace that is too hot, we recommend contacting the company.
As soon as you notice your gas fireplace getting too hot, you should turn down the temperature on the thermostat or completely switch it off.
You can also turn on the ceiling fan to better distribute heat around in your room.
You might also enjoy our post on If a Fireplace Can Explode
Can a Wood Fireplace Get Too Hot?
A wood fireplace can get too hot, sometimes without you even realizing it. The most common cause is overloading the fireplace with wood. You should check what the maximum amount of wood is for your model and size.
Simply adding one or two logs over the limit of your model could cause the fireplace to burn too hot. Rather play it safe and only put three or four medium-sized logs on the fire.
The temperature should be cozy, not hot.
How Hot Is Too Hot for Fireplace Insert?
A wood-burning fireplace insert can handle 1500°F. Anything above that would be considered too hot. It’s not really possible to measure the temperature of the fire, but you can feel the wall around the fireplace.
If you notice the wall feeling too hot to touch, that is a good indication that the fire is too hot for the fireplace insert. This is true for all types of fireplaces, including wood-burning, gas, and electrical.
How Hot Can Fireplace Bricks Get?
Fireplace bricks, also known as firebricks, are designed specifically to be used in fireplaces and furnaces. These bricks can withstand up to 1800°F, whereas normal bricks can only withstand 1200°F.
Firebricks are less porous and also have a different chemical composition than normal bricks. This is basically what allows them to be more fire-resistant.
Firebricks have a different shape and color from normal bricks. Firebricks are naturally white but can be dyed to fit any style.
Can You Make a Fire Too Big in a Fireplace?
It is entirely possible to make a fire too big in a fireplace. This is known as over-firing. This usually happens when you load too many logs into the fireplace, and the fire grows so big that the heat exceeds the recommended temperature.
Overfiring can also be caused by burning trash or paper in your fireplace, which you should never do as it could cause a chimney fire.
Rather, only put a few logs in your fireplace at a time and wait for it to start generating heat.
Will a Chimney Fire Burn Itself Out?
You should not assume that your chimney fire will burn itself out. As soon as you notice what is going on, you should call 9-1-1. The fire could spread and potentially put other people in the house in danger.
Sometimes chimneys have a slow-burning fire that we don’t see, so we don’t detect it until it is maintained again. Your chimney would have some noticeable damage.
You should regularly inspect your chimney for blockages or signs of any damage.
You might also enjoy our post on If You Can Vacuum Ashes From a Fireplace
How to Cool It Down
Understanding that your fireplace can overheat and how it happens is one thing, but what do you do next? You should cool down your fireplace when you realize it is overheating.
Let’s discuss how you can do that.
What Do I Do if My Fireplace Is Too Hot?
If you have a gas fireplace, it should be easy to simply switch off the unit. Also, most come with an automatic switch if the heat is too excessive. However, if you have a traditional wood-burning fireplace, that is not an option.
The first thing to try and do is to open the damper and separate the logs or embers as much as you can with a fire poker.
If you’re worried that the fire might damage your fireplace, you can throw a fire blanket over it.
How Do I Control the Heat in My Fireplace?
For a traditional wood-burning fireplace, you can use a damper that controls the airflow in and out of the chimney. If your fire is burning too hot, you can partially close the damper, which will restrict the airflow and limit the oxygen supply to the fire.
Gas and electric fireplaces are easier to control and usually have a temperature thermometer that you can control.
Some gas fireplace models automatically switch off if the fireplace gets too hot, this is a safety mechanism since gas could leak into your home.
How Do You Dampen Down a Fire?
While wood-burning fireplaces are beautiful and a staple piece in your lounge, they are not easy to control. To dampen a fire in your fireplace, you should try to cut off as much oxygen as you can.
A fire needs oxygen to burn, so we recommend closing all the windows, doors, and vents in the room.
Partially closing the damper below your chimney also limits the oxygen supply, in turn causing the fire to dampen down.
How Long Does It Take for a Fire to Cool Down?
A wood-burning fireplace will produce around 55000BTUs when burning at its most intense, and it could burn for about 3 hours. However, depending on the factors, the fire can also only burn at 18000BTUs for 8 hours.
The factors that influence how long a fire burns:
- Type of wood – Hardwoods typically burn longer than softwoods.
- Moisture – Wood with high moisture will burn a lot hotter and faster, potentially damaging your fireplace.
- Damper – If the damper is completely open, it allows the fireplace to use a lot of oxygen, causing it to burn warmer and faster.
Do Fireplace Blowers Really Work?
Fireplace blowers are an excellent option if you find your fireplace taking extremely long to warm up a room. They work great in a circulating fireplace, meaning air gets drawn into your fireplace, and vented back into your room.
A fireplace blower draws in air from the room, heats it up in a tube near the fireplace, and pushes it back into the room.
It helps to speed up heating the room, and there are models for both gas and wood-burning fireplaces.
Do Chimney Balloons Work?
Chimney balloons are great for short-term use, blocking any drafts coming into your room for a season or two. But they’re not the best long-term solution, since it is so much effort and most times they don’t last more than 12 months.
Chimney balloons need to be deflated before and inflated 12 hours after every use. It’s a lot of effort, and sometimes you might find your balloon lying in the hearth of the fireplace.
It does work in the short term to stop a drafty chimney, but we would recommend investing in a damper.
Do Fireplaces Need Fans?
A fireplace fan, also known as a fireplace blower, is not 100% a necessity, but it is extremely useful to have. These fans help to heat up your room tremendously, especially in the case of wood-burning fireplaces where most of the heat goes out the chimney.
A fireplace fan sucks in the air from your room and heats it up in a metal tube close to the fire, when the air reaches a certain temperature (which you can decide), it will blow the air back into the room.
It also automatically switches off when it reaches a certain temperature.
How Do I Turn Down the Heat on My Gas Fireplace?
Most gas fireplaces have a thermostat control knob which you can adjust to turn down the heat on your gas fireplace. If you find that the thermostat knob or your remote does not work to reduce the temperature, you should switch it off at the breaker box.
If your gas flame is still burning, the only option left is to close the gas valve feeding gas to your unit. The gas runs into your house via a pipe, but there is usually a stop valve near your fireplace unit.
Alternatively, you can close the valve on your gas tank, which would be outside.
How Do You Adjust the Air Mix on a Gas Fireplace?
To adjust the fuel-air mixture, you can adjust the air shutter. This is located underneath the fireplace and can be adjusted while the unit is on. You should adjust the air mix if your flame does not look accurate.
If your flame is completely yellow or orange and is producing soot, this means the air quality is too low. Adjust to introduce more air.
If your flame is very blue, there is too much air, and the air supply should be reduced.
How Do You Adjust a Gas Fireplace Valve?
The valve controls the amount of gas that is being supplied to the fireplace. Your rating plate will tell you exactly what the pressure should be. You can use a screwdriver to open and close the gas valves supplying your gas fireplace.
We recommend watching this video which is very informative and helpful in locating and adjusting your gas valves.
Your gas fireplace should be on and burning on high to ensure that the adjustment is successful.
How Do I Adjust the Air Fuel Ratio in My Gas Fireplace?
The air-to-fuel ratio on your gas fireplace determines the color of your flame and how intense your flame is burning. Luckily adjusting the ratio is easy, all that you need is a flat screwdriver.
Steps to adjust the air to fuel ration on your gas fireplace:
- Turn on your gas fireplace unit.
- Locate the control panel, usually on the side of your unit, and locate the air valve inside the control panel.
- Insert your flat screwdriver onto the valve and twist counterclockwise to increase the airflow. Twist clockwise to decrease the airflow.
- Close the panel when the air to fuel ratio is optimal.
What Is a Fireplace Mantel Heat Deflector Shield?
Mantels often get damaged due to overheating and over-firing the fireplace. To prevent these damages to your mantel, you can install a mantel heat deflector shield to deflect excessive heat away from the mantel.
If you have a mantel fireplace, we would recommend getting a mantel heat deflector to prevent the excess heat from damaging your tiles, bricks, or wood around your fireplace.
What Is a Fireplace Heat Deflector for a TV?
A fireplace heat deflector is designed to deflect heat away from your TV or your mantle. Your TV is not designed to have excessive hot air consistently blown into it, so hanging your TV above your fireplace could actually be very damaging.
Luckily, a fireplace heat deflector is a perfect appliance to force the hot air to flow in a different direction, not into your TV. It also helps to protect your mantle from heat damage, cracking tiles, or black scorching.
What Causes a Fireplace to Explode?
It’s very rare for a gas fireplace to explode, but it is possible, and thus you should do regular checks on your fireplace. Gas explosions happen when the gas builds up to a dangerous amount and ignites.
You should have a contractor regularly check your gas lines and gas tanks leading into your home. You should also regularly check the pilot light on your gas fireplace.
If this light is not sitting properly, it can cause an explosion.
Can a Wood Fireplace Explode?
The fireplace itself cannot explode, but a log can explode. However, this is not common. Logs naturally have crevices and voids where steam and gasses collect. If it builds up enough, it can cause a small explosion when you throw the log into the fire.
A good way to prevent this is simply to split your logs before placing them in the fireplace. It does not take a long time, and it might save you from a disaster.
Here is a demonstration of how to split a log.
Is It Okay to Close Glass Doors on Fireplace?
While the fire is burning strongly in a wood-burning fireplace, you should not close the glass doors. However, you can close the doors when the fire has died down mostly to minimize the oxygen supply.
If you have a gas fireplace, you should never ever close the glass doors, most glass fireplace doors are made of tempered glass.
This glass breaks and cracks due to exposure to excessive heat.
Now you understand that a fireplace can overheat and how it happens. The most important thing to remember is not to overload your fireplace with fuel, either gas or wood.
You should also look at your manual where the manufacturer would state what the maximum fuel load is for your unit.