How Long Do Patio Heaters Last thumbnail image over looking water and mountains with patio heater on deck.

How Long Do Patio Heaters Last?

In Outdoor Furniture by Jamie

Patio heaters are a great addition to your yard because they allow you to get more use out of the space at night or in the winter when it’s cold. But a lot of people are concerned about the cost of running it. Will it burn through a big tank of propane in no time at all or are they cheap to run? This guide will tell you everything you need to know about how long patio heaters last and how to calculate the cost of running one.

How Long Does a Propane Tank Last on a Patio Heater?

Most standard patio heaters run on a 20lb propane tank. The efficiency of a patio heater varies from around 80-90%, so the amount of time that it will last depends on the heater.

On a mid-range patio heater that is 100% efficient, a 20lb propane tank lasts roughly 10 hours. However, if the heater is less efficient, it won’t last as long. The change in running time will be dependent on the change in efficiency. For example, if the heater is 90% efficient, that’s a drop of 10%, so the actual running time will be closer to 9 hours. 

However, the length of time that you can run your patio heater also depends on the power. The power of the patio heater is measured in BTU and can range from 10,000 BTU to 50,000 BTU. A 10,000 BTU heater burns through 10,000 BTU worth of propane every hour. 

A 20lb propane tank contains 378,611 BTU of energy. So, on a 10,000 BTU patio heater, that propane tank will last 37.86 hours. However, on a 50,000 BTU heater, you will only get 7.57 hours.

If you want to get a good estimate of how long a patio heater will run for before you buy it, always find out what the BTU rating is. You can use the following table for rough estimates of how long a 20lb propane tank should last.

You can use the following formula to calculate the run-time:

378,611/ X BTU per hour = Patio Heater Run Time

For example, for a 30,000 BTU patio heater:

378,611/ 30,000 BTU per hour = 12.62 hours run time

This table will give you a general indication of the run-time of different patio heaters.

BTU Average Run Time
10,000 37.86 hours
20,000 18.93 hours
30,000 12.62 hours
40,000 9.47 hours
50,000 7.57 hours

A higher BTU means higher heat output. So, if you live in a very cold climate and you want to use your patio heater in the middle of winter, you’ll be looking at the higher end of the BTU scale. But for relatively mild climates, you don’t need anything as powerful and you can get one that will run for longer.

What Size Propane Tanks Can You Use for a Patio Heater?

What Size Propane Tanks Can You Use for a Patio Heater

Most patio heaters run on a 20lb propane tank. This is the standard size that you use for BBQs and other outdoor appliances. Some patio heaters will also run on a 15lb propane tank as long as you have the right regulator. You should always double check the specific brand to make sure that you’re using the right size propane tank, or you risk damaging the heater.

How Long Can an Electric Patio Heater Continuously Run?

Electric patio heaters are not limited in the same way as a propane patio heater. They plug into the mains or, in some cases, they are hardwired. So, you simply switch them on and get instant heat, and they’ll continue running until you switch them off. They have been safety checked and it’s absolutely fine to leave them on for long periods.

In theory, you can run it continuously for as long as you have working electricity in your home, as long as you can handle the big utility bills. This is why many people opt for electric heaters instead. However, you do need access to the mains, so they’re not as portable as a traditional patio heater.

How Long Can a Natural Gas Patio Heater Continuously Run?

A natural gas patio heater is fed by the gas line from your home. It needs to be installed by a professional but once it is, you don’t need to worry about it running out, as long as your gas supply is working. However, they can be more dangerous than an electric heater.

It’s important that they are in a well-ventilated area and if they are not, you shouldn’t run them for more than a few hours at a time or you risk a buildup of carbon dioxide. If they are outdoors with lots of ventilation, you can run them for as long as you like, but do not leave them running unattended because they pose a fire risk.  

Does the Temperature Affect How Long a Patio Heater Lasts?

When propane goes below 6 degrees Celsius, it stays as a liquid instead of forming vapor. This can affect the performance of appliances and your patio heater may not function as effectively. If the temperature drops too low, it won’t work at all.

However, as long as the patio heater is working, it should run for the same amount of time regardless of the temperature. That said, if it is colder, you will need to turn the temperature up and this will reduce the run time. 

Does Wind Affect How Long a Patio Heater Lasts?

The impact of the wind varies depending on the type of patio heaters. Infrared electric patio heaters do not heat the air, so they are unaffected. However, a propane or gas patio heater won’t warm you up as much on a very windy day because the heat it puts out is being dissipated by the strong winds. But does that affect how long it lasts?

The answer here is the same as low temperatures. With a lot of wind chill, you need more out of your patio heater and turning it up will reduce the run time.

Can You Use a Patio Heater During Rain or Snow?

Yes, patio heaters are designed for use in the winter so they are equipped to deal with some moisture from rain and snow. They will break if they are completely submerged, but general rain should be fine. However, the metal components can be prone to rusting eventually, so you should avoid leaving it out in heavy rain where possible.

Does the Heat Setting Determine How Long You Can Run a Patio Heater?

Yes. When you increase the heat setting on a propane patio heater, it releases more gas to create a larger flame and put out more heat. So, you’re burning more gas in a shorter space of time and the tank will run out faster. Most estimates about running time are based on using your patio heater on a medium setting.

How Many Years Can a Patio Heater Last

How Many Years Can a Patio Heater Last?

On average, a good patio heater will last around 10 years before it breaks. However, some will last less than that and some will last as long as 20 years. As you’d expect, a cheaper patio heater will not last as long. However, the lifespan is mainly dependent on outside factors.

If you live in a very rainy climate, for example, this will cause more damage and degradation to the patio heater. The more you use it, the faster the components will wear down too, so people in colder climates tend to get less life out of their heaters.

The way that you look after your patio heater makes a difference too. If you clean it regularly and carry out basic maintenance on it, you can extend the lifespan.

What Causes Patio Heaters to Stop Working? 

There are several things that can cause patio heaters to stop working. If the flame will not stay lit, there is likely an issue with your pilot light or thermocouple. The pilot light can move out of place so you may need to bend it back into place with some pliers. 

There could also be problems with the gas line. If there are holes in it or a blockage, this stops gas from coming through the line, so the flame does not burn properly. It could also be that the regulator on the gas line is not functioning properly, so gas is not being released from the tank.

The ignitor that gives you a spark to light the flame can fail too. In this case, you can use a stick lighter to light the flame instead. 

If you check for these issues and can’t find anything wrong, it may be that your patio heater is broken beyond repair and you need to replace it.

How Can You Prolong Your Patio Heaters Lifespan? 

There are some simple things you can do to make your patio heater last longer. 

First up, keep on top of routine maintenance:

  • Check the hoses for damage and look for signs of splitting or holes
  • Look for leaks where the hose meets the cylinder
  • Check vents and air holes for blockages

If you spot any problems, do not ignite the patio heater until you have sorted them.

Cleaning your patio heater is also very important. Remove the screen to expose the burner and clean away any dust and debris. Letting this dirt build up can cause problems with the burner and stop the heater from working properly. You can use pipe cleaners to get inside individual vents and ports. Then, wipe the surface down with some soapy water (avoid abrasive cleaners). You can also use automotive wax on the outside of your patio heater to give it a nice shine and protect it from the elements.

Storing the patio heater properly makes a difference too. Although they can be used outside, constant exposure to the elements will cause them to degrade faster. Most heaters come with a cover and you should always use it whenever the patio heater is not running. If possible, store the heater in a garage when you are not using it. 

These simple tips will help you keep your patio heater running for years to come.

Patio Heater FAQs

Can Running a Patio Heater for Long Periods Be Dangerous?

In theory, it should be fine to run a patio heater for long periods, if it is working correctly. It can be dangerous if you run it in a poorly ventilated space but otherwise, you should be fine. However, it can cause unnecessary damage to your heater if you use it for extended periods.

What Does BTU Mean? 

BTU stands for British Thermal Unit. It is a measure of the amount of energy it takes to heat one pound of water by one degree Fahrenheit. So, it takes 1 BTU to heat a pound of water by one Fahrenheit.

This is a standard measure of heat output that is used around the world. You’ll find it on a lot of appliances like radiators, as well as patio heaters. 

Can You Buy Different Size Patio Heaters? 

Yes, you can buy different sized patio heaters. Larger heaters will have a bigger BTU output, meaning that they can heat a larger area. These larger heaters will burn through propane faster (as outlined in the table above) so they are more expensive to run. When you are choosing a patio heater, you should consider the area that you are trying to heat and pick one that is a suitable size.

Is it Expensive to Operate a Patio Heater?

A 20lb propane tank costs between $15-$20 to refill. If you’re using a mid-sized patio heater that puts out 30,000 BTU, it will go through that in 12.62 hours. That works out as roughly $1.58 per hour (based on a $20 tank). In comparison, a 1,500W electric heater costs around $0.20 per hour to run. So, patio heaters are fairly expensive, but you’re not going to be running it constantly. It’s something that you will have on for a few hours at a time, and only at certain times of the year, so if you spend a lot of time in the yard, it’s worth it.

Final Thoughts

Patio heaters can burn through gas quite quickly if you buy a large one. However, most people don’t need that much heat. If you just want a nice warm seated area, look at the smaller end of the scale. You don’t need a 50,000 BTU heater unless you are operating a commercial space. Buying a reasonably sized one and looking after it properly will help you limit your gas consumption and cut the costs of owning a patio heater.

About the Author

Jamie

Jamie is the founder of The Backyard Pros. When he was 15 years old he started working at a garden centre helping people buy plants, gardening products, and lawn care products. He has real estate experience and he is a home owner. Jamie loves backyard projects, refinishing furniture, and enjoys sharing his knowledge online.