Are you planning on using a propane tank for your fire pit? If so, then you’re probably wondering how long it will last.
A propane tank for a fire pit lasts between 2 and 43 hours. Generally, larger tanks last longer than smaller tanks. A lower heat output may cause a propane tank to last even longer.
Keep reading to learn more about how long a propane tank lasts for a fire pit and tips to make the most of your propane tank.
A Propane Tank Lasts 2 – 43 Hours for a Fire Pit
Propane tanks for fire pits generally last between 2 – 43 hours, though the duration varies with the size of the tank and the BTU output of the burner.
Here’s a quick table to give you an idea of how long different-sized propane tanks will last for your fire pit at heat outputs of 40,000 BTUs/hr and 50,000 BTUs/hr, respectively.
| 40,000 BTUs | 50,000 BTUs | |
| 5 lb (2.27 kg) | 2.15 hrs | 1.72 hrs |
| 20 lb (9.07 kg) | 8.6 hrs | 6.9 hrs |
| 40 lb (18.14 kg) | 17.2 hrs | 13.8 hrs |
| 60 lb (27.22 kg) | 25.8 hrs | 20.6 hrs |
| 100 lb (45.36 kg) | 43.0 hrs | 34.4 hrs |
How long will a 20lb propane tank last on a fire pit? Approximately 4 to 5 hours if you have it at it’s max output! But could very well last closer to 8 or 9 hours at a lower output.
What about at 30,000 BTU? Around 12 to 14 hours.
Propane produces 21,548 BTU/lb. Since most propane tanks are filled to 80% capacity, a 5 lb tank would be filled to 4 lbs (1.81 kg). Therefore, the tank would produce 4*21,548 = 86,192 BTUs.
At 40,000 BTUs/hr, the 5 lb (2.27 kg) tank would last 86,192/40,000 = 2.15 hrs.
At 50,000 BTUs/hr, the 5 lb (2.27 kg) tank would last 86,192/50,000 = 1.72 hrs.
The same logic applies to the remaining estimations. Keep in mind that the estimates increase when the tanks are filled to capacity.
Factors Determining How Long a Propane Tank Lasts
Now that you know the basics of how long a propane tank lasts, let’s take a closer look at the factors that affect its duration.
Larger Tanks Last Longer Than Smaller Tanks
As you might have noticed from the table, the size of your propane tank is the first factor that determines how long it will last.
All factors held constant, a larger tank will last longer than a smaller tank, which makes sense since a bigger unit can accommodate more fuel. Conversely, a smaller unit will run out of fuel more quickly.
That said, you’ll also have to pay more for a larger tank. So, it’s important to find the right balance between the size of the tank and how often you plan on using your fire pit.
Higher BTU Output Means Shorter Burn Time
The BTU output is the second factor that determines how long your propane tank will last.
BTU stands for British Thermal Units, a measure of the heat output of your fire pit burner. The higher the BTU output, the more fuel your fire pit uses, and the shorter your propane tank will last.
On the flip side, a lower heat output means that your fire pit uses less fuel. Therefore, with a lower BTU output, you can expect your propane tank to last a bit longer.
Lower Outside Temperature Means Shorter Burn Time
The third factor that affects how long your propane tank lasts is the temperature outside.
You might not realize it, but fire pits actually use more fuel when it’s cold out. That’s because they have to work harder to maintain a consistent temperature.
Therefore, if you’re using your fire pit in the winter, you can expect your propane tank to run out more quickly. In contrast, a fire pit used in the summer will last longer since it doesn’t have to work as hard to stay lit.
The Wind Can Quickly Drain a Propane Tank
Believe it or not, wind is another factor that determines how long your propane tank lasts.
If you live in an area with a lot of wind, then you might have noticed that it can quickly drain a propane tank. That’s because the wind blows away the heat from the fire, and the fire has to work harder to stay lit.
Therefore, if you’re using your fire pit in a windy area, you can expect your propane tank to run out more quickly.
How Do You Know When the Propane Tank Is Getting Low on Fuel?
There are several signs that indicate when a propane tank in your fire pit is running low on fuel:
The Flame Is Lower Than Usual
One of the first signs that your propane tank is getting low on fuel is a flame that is lower than usual. If you notice that the flame is no longer as high as it used to be, then it’s likely that the tank is running low on fuel.
If you’ve been using your fire pit for a while, then it’s normal for the flame to get lower. That’s because the tank is getting closer to empty, and there’s less fuel to burn.
Related information: Why does my fire pit smell like propane?
The Flame Is Yellow Instead of Blue
Another sign that your propane tank is running low on fuel is when the flame is yellow instead of blue.
A healthy flame should be mostly blue with a small yellow tip. However, if the flame is mostly yellow, then it’s a sign that the tank is running low on fuel, causing incomplete combustion.
Note: An interruption in air supply can also cause your fire pit to have a yellow flame. So, you might need to check the vents to make sure they’re not blocked.
The Flame Is Flickering
If you notice that the flame is flickering more than usual, it’s another sign that the tank is running low on fuel.
A flickering flame is usually caused by a lack of oxygen. However, it can also be caused by a low level of propane in the tank.
The Fire Pit Is Making Strange Noises
If you notice that your fire pit is making strange noises, it’s another sign that the tank is running low on fuel.
Normally, a fire pit should only make a soft hissing noise. However, if you start to hear popping or crackling noises, it’s a sign that the fuel in the tank is running out.
The Fire Pit Is Not Getting As Hot as Usual
A fire pit that’s running low on fuel will have a hard time reaching and maintaining high temperatures. As a result, the fire pit will not get as hot as usual.
If you notice that your fire pit is not getting as hot as it used to, be sure to check the level of propane in the tank.
Tips for Making the Most of Your Propane Tank
There are a few things you can do to make the most of your propane tank and extend its lifespan:
Use a Wind Guard To Minimize Heat Loss
If you live in a windy area, then it’s a good idea to use a wind guard. A wind guard is a piece of equipment that goes around the fire pit and protects it from the wind.
By using a wind guard, you can prevent the wind from blowing away the heat from the fire. As a result, your fire pit will use less fuel and your propane tank will last longer.
Reduce the Gas Flow
If you want your propane tank to last longer, it’s important to reduce the gas flow.
The gas flow is the amount of gas that’s released from the tank and goes to the fire pit. By reducing the gas flow, you can make the flame smaller and prevent the fire pit from using too much fuel.
To reduce the gas flow, simply turn the knob on the propane tank to a lower setting.
Turn Off the Fire Pit When You’re Not Using It
Another way to extend the lifespan of your propane tank is to turn off the fire pit when you’re not using it in order to save fuel.
That said, here’s a quick video tutorial from Chowhound on how to tell how much propane you have remaining in your gas tank:
Conclusion
Now that you know how long a propane tank lasts for a fire pit, you can plan accordingly and make sure that you have enough fuel to last through the night. With these tips, you’ll be able to make the most of your propane tank and enjoy your fire pit to the fullest!
