Patios, decks, and gardens can be expensive, so spending more time outside and appreciating your surroundings makes sense. Many individuals add a propane-fueled heater to their outside space to increase their usable time, but simply…

How long will a gas tank for a patio heater last?

Average patio heater will use approximately 1kg of gas (propane/lpg) per 12kW of power.

The average BTU usage of an outdoor propane-fueled heater is 42,300 BTUs. A full 20lb propane tank contains 432,000 BTUs.

When the tank’s BTUs are divided by the heater’s BTUs, you get 10.21 hours of heat. It is a good idea to round down for lighting and tank weight accuracy.

A 20lb propane tank, or around 4.7 gallons of fuel, is typical of a portable propane patio heater. A 20lb propane tank can last up to 10 hours and costs $15 – $20 to fill, resulting in an average cost per hour of $1.5 – $2.

A standard 40,000 BTU patio heater will cost approximately $1.70 per hour to operate.

Because there are no upfront fuel expenditures, natural gas patio heaters are less expensive to operate than propane patio heaters.


We have discovered a number of factors that influence the mathematical solution. How many times you light it, how difficult it is to ignite, and whether or not the tank contains a full 20 pounds of propane.

Continue reading to find out how long a propane tank may last you!

Why should you use a propane tank on the patio heater? 

Patio heaters can be powered by a variety of fuel sources, the most common of which are electric, propane, and natural gas.

Propane tanks are a popular choice since propane-fueled patio heaters can provide various advantages over other techniques.

Most portable styles house the propane tank inside the base of the heater.

Propane is non-toxic, so it will not harm the water or soil in your yard—great news for gardeners!

You should be able to easily set up the propane tank to complete the task. You also don’t have to be concerned about upkeep.

What factors could shorten the time it takes my patio and deck heater to heat up?

We have previously touched on the basic causes, but we will go into greater detail for you.

Tank Capacity

For example, if you have your propane tanks filled by someone, are the tanks weighed? If so, it should be more than 20 pounds for the tank’s weight.

Most fillers fill the tank until it no longer holds any more propane, which should give you between 15 and 20 pounds of propane.

Many folks employ tank exchanges, which typically fill tanks to 15 pounds. What? Yes, but hopefully, they will reduce the price.


Attempting to Light

If you don’t yet have a heater, you most likely have a gas grill. Sometimes the puppy lights up like a flash, and other times you’re left wondering, “Is the piezo ignitor even sparking?”

How easy it is to light the heater depends on how full the tank is and the weather conditions. A little wind, for example, on a day when the tank is cold and only half-full, will light differently than a non-windy day with some sunshine on it.

The latter increases the pressure in the system. Despite the presence of a pressure regulator, it has a wide range of operations.

Mechanical Situation

If your heater is brand new, the airlines must be vented. If it is older and has had some heating experience, the thermocouple may be damaged or dusty, making it difficult to ignite or stay on.

Of course, this means you’re wasting propane by trying to keep it going.

Check out this post to discover how to clean or replace your heater’s thermocouple!

How much propane is wasted when attempting to light a patio heater?

The amount of propane lost is very dependent on your specific circumstances. However, if you operate your heater for three hours at a time and only have to light it once or twice every tank, you should only lose roughly 0.50lb to 0.75lb of propane per tank.

How much does it cost per hour to heat the patio?

Check out the calculator above to get an idea of how much your tank will cost in your location.

The weight of propane per gallon is approximately 4.24 lbs. A full 20-pound tank stores 4.7 gallons of propane.

At the time of writing, the national average for propane was around $3.65 per gallon (when filling a tank). As a result, a 20-pound tank filling would cost roughly $17.22. Check your local prices; they may be different.

How much propane is in the exchange tanks?

We discussed this earlier, but a 20lb swapped propane tank typically contains roughly 15 pounds of propane. This suggests that exchanging the cylinder or tank should cost around $12.91.

I know I exchange my tanks for the sake of convenience and time restrictions. Getting a decent shape tank refilled is your best idea, but weigh it when you get home to see how much they truly put in there.

What if you use a lower heat setting on the heater? So, how long does it last?

This appears basic. However, manufacturers do not often promote the decreased heat setting BTUs. However, in order to better understand it, we shall convert the heat output into a percentage.

If the maximum setting is 100 percent, a lower level would be…say…50 percent. As a result, your BTUs are cut in half, allowing your tank to last twice as long.

We will remark that an adjustment knob less than 50% will lose its ability to radiate heat and combat the cold or chilly elements of the outdoors.

Calculate How Much Propane Your Heater Will Use

Let’s calculate how much gas an outdoor heater consumes.

  1. Determine the weight of your empty tank. It may be referred to as tare weight, and it should be printed someplace on the tank’s label.
  2. Subtract the tare weight from the total weight of the tank.
  3. Divide the total weight of the full tank by 4.24, which is the weight of one gallon of propane in pounds.
  4. One gallon of propane produces 92,000 BTUs per hour. Each gallon will burn for 1.84 hours if you have a 50,000 BTU patio heater. (92,000 BTUs per gallon/50,000 BTUs for a heater rated at 50,000 BTUs = 1.84)

The formula above will give you the burn rate of your propane heater.

To determine how long it will burn, perform the following calculations.

Assuming your heater has a 40,000 BTU rating, a 20lb tank will last for:

92,000 / 40,000 = 2.3 x 4.24 = 9.752 hours

Assuming your heater has a 60,000 BTU rating, a 20lb tank will last for:

2.3 times 4.24 equals 6.5 hours

After all, I ended up performing the math for you!

Running Costs Comparison: Propane vs. Electric Heaters

Now that you know how much gas your outdoor heater will consume, you may have another question.

What about the use of electric heaters? Is it more cost-effective to use it instead of propane?

Let’s see how it goes.

On the surface, a comparison of the price you pay locally for electricity per kilowatt hour and the cost of propane may appear to show that electricity is less expensive.

However, if you delve a little deeper, you will discover that the solution is more complicated. Because the price is determined by the equipment in use, let us concentrate on heaters because we are interested in them.

If you operate a 2,500-watt electric heater for 8 hours a day, you’ll be looking at around 20kWh. In that time frame, the same heater would use.068 gallons of propane, which is equal to 8530 BTUs per hour.

In the preceding case, a gas heater is 20% less expensive.

But here’s another arithmetic challenge for you to solve. The initial cost of a propane heater—or any gas heater, for that matter—can be double that of an electric heater.

However, assuming the heater does not break down a few months after you buy it, the propane heater will still save you money in the long run.

Can a Patio Heater Be Converted to Natural Gas?

In a nutshell, sure. You do, however, lose the ease of portability. Assume you have a natural gas pipe running through your yard.

In that scenario, you can use a natural gas heater by replacing the regulator and, depending on the manufacturer, the orifice if it is not incorporated into the regulator.

For the average homeowner’s safety, we recommend purchasing a natural gas patio heater, to begin with.

Amazon has a fantastic natural gas-fueled outdoor heater for residential or business use. Learn more about this natural gas outdoor heater by clicking below.

What Are the Other Patio, Deck, and Garden Heater Options?

There are two types of categories;…

Gas and electricity Propane and natural gases can be separated from the gas.

There are advantages for each, and to add our two cents in…

Electric patio heaters are best suited for stationary applications, such as in a gazebo or pavilion, or at least adjacent to an outlet so that people do not trip over the cables and knock them over.

Natural gas is also limited due to its natural gas supply line. This should not be something that is lying on the ground.

Because propane gas is an enclosed heat delivery system, it is the most portable for open heating spaces.


And because propane burns effectively, it costs less to run your heater than an electric heater would. So, while buying a gas patio heater is more expensive up front, it will save you money in the long term.

Keep all this in mind when you narrow down your options, and you’ll be grateful for your pleasant heated patio on those cool fall nights.

Last update on 2024-06-22 / Affiliate links / Images from Amazon Product Advertising API

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