Top Patio Heater FAQs

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Summer is gone; your patio isn’t. It makes perfect sense to refuse to say goodbye to that cozy space just because temperatures are starting to drop. The good news: with an appropriate heater, you don’t have to. Before you get started, though, review this top patio heater FAQs for all the tips and tricks!

A patio heater, as its name implies, is designed to keep your outdoor space comfortable during fall and winter. To this end, all models will share a basic resilience your ordinary heaters won’t have, so they can function the way they are supposed to while being outside.

Some run on gas, and will therefore require a compatible tank. Others are electric; this latter option is more versatile in terms of size and placement—some will stand, some are for wall-mounting, and some others will comfortably hang from the ceiling; certain models will even be compatible with multiple installation options.

When you shop for a heater, you want to make sure you’re giving your area appropriate cover for its size. Let that be our starting point for this compilation of FAQs.

How Big of an Area Does a Patio Heater Heat?

Answering this question is a bit tricky: as heaters vary in size, fuel and configuration, they do as well in terms of potency. They’re not even measured in the same way—electric heaters go by wattage, whereas those that run on gas use a unit called BTU (British Thermal Unit, the equivalent to the energy required to raise the temperature of 1 pound of water by 1°F) to rate their heat output.

The immense majority of gas patio heaters will tell you their BTU capacity somewhere in the literature. The electric ones will tell you their wattage. 1 watt is equal to 3.412142 BTUs per hour. Thus, you can obtain your electric heater’s output via the following formula:

(W) * 3.142142 = BTU/hr

W is your heater’s watts. This way, you can translate it to a number you can use for our next query.

Outdoor heater close up

How To Determine How Many Patio Heaters I Need

Now we’re getting somewhere, aren’t we? We should start by saying, whenever we are talking of heating up an entire home, calculating your BTU needs can be complex: walls and their thickness, windows and their size, ceiling height, are some of the factors to be taken into account. Patios, on the other hand, are simpler, as they tend to be fairly open spaces. Bear in mind, however, that this is an approximation, albeit one that should serve you well enough.

Begin by obtaining your patio’s square footage. Since most patios are a rectangle or square, this should be as simple as multiplying width by length. Once you have this number, multiply it by 20. For example, if your patio is 350 sq ft, then 350 x 20 = 7000, you need a heater with 7000 BTUs.

As we mentioned before, this is only an estimate. If your winters are particularly harsh, it is recommended to swap that 20 for a number between 50 and 60. If your patio is of irregular shape rather than a square or rectangle, consider dividing it into several areas and placing a smaller heater of suitable potency in each of them.

Using a Patio Heater Outside in Different Types of Climates

Patio heaters are made to be used outside, but they’re not necessarily equipped to hold up to all types of weather. Here’s some things to consider before choosing the best heater for your patio or yard.

Can You Leave a Patio Heater in the Rain?

This will depend on your heater. Those that run on gas, while designed to work outside, will deteriorate quicker if left out in the snow and rain. Electric heaters are a bit of a mixed bag—some will endure the elements better than others. Our next answer will cover this more in depth.

Are Patio Heaters Waterproof?

As they are intended for working outside, heaters that run on gas will be just fine when exposed to a certain degree of humidity or small splashes. That said, they are typically not designed to stay out in the rain, and should be brought into cover if the weather changes.

In other words: rather than waterproof, gas patio heaters are water resistant. Electric types, on the other hand, will vary by model. How to tell, then, which electric heaters are waterproof and which aren’t? By looking at the relevant number.

What Does The IP Rating Mean?

Created by the International Electrotechnical Commission (IEC), this system is intended to express, in a brief and clear manner, how resilient an electrical enclosure is against the elements.

Many kinds of outdoors devices, such as TVs, projectors, speakers and, yes, heaters, will show this rating somewhere in their literature. The rating’s format is as follows:


The first digit is for protection against solids, i.e. dust. The second digit expresses the level of resistance against liquids. This is the one that tells us if a device or appliance is waterproof. The higher the number in the relevant field, the better the protection, with each level signifying a fairly specific strength.

Take, for example, an IP32 rating: this means the enclosure is protected against solid foreign objects of 2.5mm and greater (3), and against vertically falling water drops when enclosure is tilted up to 15°.

In this example, this item is not waterproof (this rating is so low, manufacturers would not bother to show it); waterproof begins at liquid protection 5 (protected against water jets), although this still doesn’t mean it can be fully immersed—that would be at least an 8. You can find out more about this system, as well as see the official table, by clicking here.

Worth noting: it is not rare to find products whose rating shows an X on the first position (for example, IPX6), which means that protection against solids was not tested.

This needs not be cause for alarm: as long as the other protection is high enough, then it stands to reason that dust and other solids won’t be that big of a problem either.

Snow on a backyard patio

Do Patio Heaters Work in the Winter?

Winter is, precisely, when we most want to benefit from our heater; thus, it stands to reason we want to know if our appliance will even work. In most cases, it will—though there is one caveat.

What to do When Propane Won’t Flow

Maybe it has happened to you before: you really need that source of warmth, but no gas will come out. This can be due to a variety of causes:

Extreme ambient temperatures. First, something you may not know: while it is sitting in your tank, propane is a liquid, not a gas. At a temperature of -44°F, propane boils and turns into vapor, which is what flows through your regulator and out the burners; while it is in the tank, the high pressure at which it is stored prevents it from vaporizing; when you open the valve, the pressure is released, and the conversion happens.

If the propane cannot reach its boiling temperature, then it won’t vaporize, and your heater will essentially not work. Few places will ever go below 44°F, but if it happens, then the propane will stay in liquid state.

Frozen components. This can happen even if the propane is at a proper temperature for vaporizing. Condensation can set into the regulator or valve, preventing them from doing their job.

Too much pressure. Have you ever used a can of pressurized air? If so, you likely have noticed the can gets very cold after a short while using it. This is because, as it evaporates, the air within the can draws heat from its surroundings. Same happens with propane: as it turns into vapor, the tank’s temperature drops; if it goes below the optimal level for evaporation, then your propane won’t come out.

Keeping the Gas Going

So, how can you go about preventing it? A good way to begin is by keeping the tank as full as possible; low propane in the tank makes it more likely to frost, as there is more vapor within. Preserve it from the worst of the cold, too. An appropriate blanket will go a long way.

Face the vent down so it won’t get clogged by snow or ice, and cover the valve and regulator with a rag or an empty milk carton, always making sure to leave the vent unobstructed.

Where Can You Set up a Patio Heater?

If you’re planning and event and want to keep your guests comfortable then it makes sense to look at patio heaters to keep that outdoor space warm. Keep in mind, though, that not all patio heaters can be set up in all spaces; here’s some tips for heating various tricky spots.

Outdoor event tent for a wedding or party

Can You Use a Patio Heater Under a Covered Patio?

If it is an electric heater, then you have nothing to worry about; plug it in, and enjoy. If, on the other hand, your heater runs on propane, then the answer becomes a little more complicated.

It’s mostly about ventilation: if your patio is wide open, then we’re off to a good start, but you should also make sure there is enough space between the heater and the ceiling.

Anything that releases smoke (specifically, wood) is better off in the open, with nothing overhead.

How Close Can a Patio Heater Be to the Ceiling?

Your electric wall-mounted heater should be about half a foot away from the ceiling; if it stands at ground level, then the ceiling will be of no concern.

Propane heaters are a different matter. Normally, your manual will specify the distance you should keep between your appliance’s top and the ceiling. That said, it is usually advised to maintain 2 feet (preferably 3) clear all around your heater; this includes the ceiling.

Can I Use a Patio Heater in a Party Tent?

Just because it’s winter, doesn’t mean the big days and celebrations stop coming. I for one know people whose birthday and wedding anniversary are in December; you probably do too. And who likes going to cold parties?

The answer is yes: you can use a patio heater in a party tent. Propane will be better for this job, as it is more portable due to it not being limited by a cord. Just be sure to have enough clearance (your heater’s manual is the best bet for finding this out), and try to add some walls and a floor to your tent so there will be some insulation to keep the heat in.

One last thing: do your best to keep the heater going uninterrupted while the celebration lasts. Turning it on and off at intervals may cause uncomfortable fluctuations in temperature.

Can I Use a Patio Heater in a Garage?

If it is electric, then the answer is yes; set it on the ground, mount it on the wall, attach it to hang from the ceiling, and enjoy the warmth.

If you go for propane, choose your unit according to the space you intend to keep warm, so you won’t overheat; and don’t forget about safety measures, which we will cover in depth further down.

Can You Use Electric Patio Heaters Indoors?

If your heater is infrared (as opposed to halogen), you can. The main drawback would be the cost-to-convenience ratio: most electric heaters intended for the patio are more expensive than their ordinary indoors counterpart due to their resilience (a high IP rating is not free).

The relevant precautions will be covered further down.

Can I Use a Patio Heater Indoors?

The only case in which this is permissible is mentioned above: electric infrared patio heaters. Halogen and gas-powered heaters intended for a patio are just too powerful for being inside the house, and there’s more risk of something flammable coming too close, with predictable consequences.

In summary: if it is for the patio, it should stay in the patio.

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

Propane tank to heat a patio heater

Taking an average heater, with an output around 40,000 BTUs and coupled to a standard 20lb propane tank, the answer would be around 10 hours. That said, the output of a propane patio heater will vary, mostly depending on its size. A heater with a higher output will go through your tank faster than a weaker appliance. If we want a more precise number, we need to do some math.

Per the U.S. Energy Information Administration (EIA), a gallon of propane generates 91,452 BTUs. One 20lb tank of propane has a capacity of 4.6 gallons, or a total of 420,679 BTUs. You divide this by your heater’s output, and you get how many hours you can expect one tank to last. If we go by that 40,000 average we were talking about on the paragraph above:

420,679/40,000 = 10.51

You get roughly 10 hours. Consider, as well, that heaters don’t burn 100% of the propane that goes through; most will burn at about 90% efficiency. With this in mind, it’s wise to shave the number down a bit, for good measure.

How To Light a Patio Heater Manually

Fans of propane have it a little harder: whereas electric heat sources only require the push of a button (or turn of a knob) to begin working, those that run on gas require a few steps to start up.

Shielding a lighter from the wind while outside

Before You Begin

This is gas we’re dealing with, and it’s no trifling matter. Here’s what you should do before you move on to starting the heater.

  • Clear obstructions. This is especially important when it comes to the burner. Dust, cobwebs, debris and the like, all of it should be plucked away. The area around the heater should be cleared of anything flammable, too.
  • Check the heater. Look for parts that might be broken or out of place; this might save you some scares down the road.
  • Watch the regulator. It should always be closed while the heater is not being used. Verify it is not open before each use.
  • Stay alert for leaks. If it smells like gas (when you open the regulator, for example), stop what you’re doing and find where it’s coming out of. Fix it before anything else.
  • Verify the tank is full. This is mostly so your merry times won’t be interrupted by your heater going out due to having run out of fuel.

Knowing Your Heater

How exactly you turn on your heater will depend on its design, and reading the user manual is highly recommended in order to familiarize oneself with the specific process. Here are a few things to learn from it.

Ignition System

Many models come with a Piezo system, which consists of a button you press to create a spark, making ignition fairly easy. If your unit does not come with this system, or it no longer works (which can happen), then the procedure will be a little different. In some cases, the ignition button and flame knob will have to be pressed down at the same time.

Gas Valve Requirement

Heaters that don’t have a Piezo ignition system will often require you to close your tank’s valve before you start up the unit.


If your heater doesn’t have one, then starting it will be a more hands-on process.

The Steps

To reiterate, this process will vary depending on your heater, and reading the user manual will make this much easier. That said, here’s a summary of how it’s done.

A. Pilot (Automatic Ignition)

  1. Begin by pushing the control knob inwards. Keep it pressed, and turn it to the pilot position; this is usually done by moving it about 45° counterclockwise.
  2. Turn your gas tank’s valve all the way to open. You should see a small, blue flame now. If you do, proceed to the next step. If you don’t (or, more importantly, if you smell a leak), turn the gas off again. We’ll cover troubleshooting further down.
  3. Time to ignite. If you have an ignition button, press it until the pilot takes on a slightly larger, orange flame. If there is no such button, or it doesn’t work, apply a match or lighter; candle lighters are often recommended for this.
  4. Release the pressure you’d been applying on the knob. Once your hand is fully away, and the flame remains, you can turn the knob to regulate your flame.

B. No Pilot (Manual)

  1. In this case, you start by making sure your heater is completely off; that there is no flame. That verified, turn your tank’s valve all the way up.
  2. There’s no ‘pilot’ position to bring the knob to. Instead, turn it to low, as low as it allows. Keep it pressed.
  3. Ignite it. Either press the ignition button, if you have one, or apply your trusty candy lighter. Maintain the pressure on the knob even after you see a flame; give it 45 seconds to a minute.
  4. Slowly release the knob. If the flame stays, you can now regulate your flame’s intensity, and start your good times.

Troubleshooting Patio Heater Installation

Every now and then, your heater may refuse to start up. Here are a few possible reasons.

  • Gas leak. Check the hose carefully for any holes or tears, however small they may be. It might be time to replace the hose altogether.
  • Gas tank not connected. The connection itself might be faulty as well. For good measure, it’s can’t hurt to disconnect the hose, and reseat it.
  • Clogged hose. Remove it and check for obstructions.
  • Empty tank. If there is no more gas, the heater cannot start.
  • Obstructions. Check the burner and bug screen; clear away any debris sitting on them.
  • Regulator. It might be switched off, or faulty. Verify that it works and that it is in the right position.

How To Use Patio Heaters Safely: Our Tips

The following precautionary measures apply no matter where you decide to place your heater: outside, in the patio, in a garage, a tent or in your living room (if it happens to be of the right type and size).

A. In General

These are actions that should be taken, regardless of whether your heater runs on gas or electricity.

  • Watch the clearance. The user manual will usually tell you how much space to leave between the heater and pretty much anything else (walls, ceiling, furniture and so on); it is highly recommended to abide by it. Remember to keep your children and pets away too.
  • Inspect it periodically. Look for parts that might be broken or out of place, before any use. Keep it clean, as well: obstructions or foreign agents might cause malfunction or overheating. Letting a professional do a thorough inspection every once in a while is highly recommended, especially for gas heaters.
  • Mind the fuel line. Be it a power cord or a gas hose, take a closer look at it periodically; you don’t want leaks to develop or sparks to jump around. To the extent that this may be possible, place the hose or cord in such a way that there is little to no risk of somebody stepping or tripping on it.
  • Look for certification. UL and CSA are two of the most reputable seals of approval. A unit with such a rubber stamp is a unit that was rigorously tested for resilience and reliability.
  • Read the manual. Doing so will help you quickly familiarize yourself with your heater’s inner workings, its safety features, and how to solve problems that might arise.
  • Never leave it unattended. Heaters come with a variety of safety features built in, designed to shut the unit down if there is a drastic change. That said, it is better for you and yours if there is a responsible adult nearby to react quickly if something happens, or if a kid or animal wanders too close. Remember to turn the heater off when you will no longer be in the area.
  • Don’t move it while it is working. Shut it off, disconnect it from its fuel source (outlet or tank), wait until it is cool. Only then is it safe to change its location.

B. Propane and Gas Heaters

Gas and an open flame should be always approached with care. Here’s how to make use of your gas-powered heater more safely.

  • Use your heater where you’re supposed to. Do not attempt to bring a heater intended for a patio, into a more closed off area like your living room.
  • Always check the hoses and connections before you start your heater. Be alert in case you smell a leak; if it smells like rotten egg, turn off all valves.
  • Find and address leaks before anything else. Prepare a solution of equal parts liquid soap and water, apply it liberally on the hose and connections (a spray bottle works well for this), and look for bubbles. If it is a faulty connection, reseat it. If the leak is on the hose itself, discard and replace it.
  • Act without delay if you smell gas but can’t find the leak. Turn off the valve, disconnect the tank from the heater. Turn off anything that might throw a spark (lights, appliances, electronics such as cellphones); evacuate the area and call 911.
  • Ensure there is plenty of ventilation before starting the heater. This is so your flame can breathe as it needs, and to prevent carbon monoxide accumulation.
  • Don’t let just anyone operate the heater. Kids should be 15 years or older before you consider letting them help.
  • Check that your flame is blue. If it is orange or yellow, it means it’s not burning properly. Shut the unit down immediately and contact your technician.
  • Do not use aerosols in the vicinity. Fresheners, hair spray, deodorants; all of these should be used far away from the heater while it’s on.
  • Install carbon monoxide detectors in the area. This is especially important when you’re using a propane heater intended to be indoors, but it doesn’t hurt to place them near your outdoors heater. Many units are battery-powered, so they will work even if there is a blackout.
  • Disconnect the tank every time you’re done using the heater. Don’t forget to put the tank away.
  • Store your tank appropriately. Do not place indoors, and ensure there’s plenty of ventilation. Remember to do what you can to preserve it from extreme cold.
  • Handle the tank with care. If the valves get damaged, it might become unusable, or worse.
  • Keep any spare tanks 20 feet away from the heater. This is especially important while the heater is on.
  • Maintain your tank in an upright position. Do not use or store it upside down, or tipped over.

C. Electric Heaters

Heaters of this sort are easier to operate safely, as there is no open flame or emissions to worry about. Thus, there are fewer recommendations to make (in addition to the general ones we listed above).

  • Seek models with safety features. These will vary depending on their configuration. For example, those that are intended for standing on a tripod may include a tipover protection that will instantly turn the unit off if it tilts too far from the vertical. Other features you might want are a timer, so you don’t have to worry too much about accidentally leaving the heater on overnight; and overheating protection, in case the filament gets too hot.
  • Don’t touch it while it’s working. The surface can get really hot; this is why it’s important to keep children and pets away.
  • Respect its IP rating. If it’s not intended for exposure to rain, don’t place it all in the open. Remember: electricity and water don’t mix.

What Is Radiant Heat?

Most of us feel this sort of heat quite often: all we have to do is feel the sun.

Radiant, or thermal radiation, is a form of heat transfer, like convection and conduction. The first two require a medium to propagate: convection works in fluid bodies such as water and air, moving the heat around as position changes (hotter air rises, cooler air descends); conduction is seen among conductive materials such as metals. Radiant heat, on the other hand, goes directly from one body to another, depending on temperature difference: bodies with lower temperature absorb heat from those that are warmer, and they transfer it to those that are cooler.

While the word ‘radiation’ may evoke unpleasant feelings, it’s quite harmless, and it is harnessed by infrared heaters; it’s considered the most efficient way of warming up, as you don’t have to expend additional energy to heat up the air before you feel the effects.

Are Electric Patio Heaters Better Than Gas?

The answer to this is largely subjective; there will always be those whose personal preference leans one way or the other. That said, there are a few advantages to be named for electric patio heaters.

  • Safer. There is no need to worry about an open flame, gas leaks or accumulation of emissions; this is why outdoor patio heaters can also be used indoors. They are easy to start up and shut down, too: no matches, valves and the like.
  • Bells and whistles. Aside from safety features (overheating and tipover protection, for example), electric heaters are more likely to incorporate perks such as timer, operation via remote control, and multiple installation options.
  • Resilient. It is actually possible (and not that hard) to find electric patio heaters that can be exposed to rain and even snow without fear of decay or malfunction.

This is not to say that propane heaters are without their own good selling points. Here are a few:

  • More portable. Electric heaters can’t stray far from walls and outlets. With gas-powered heaters, your fuel goes where your heater goes.
  • Quicker heat, wider range. Some electric heaters can take a while to have any effect. They will only apply heat in the direction they are pointed, too. Gas-powered heaters provide warmth all around them, and to a larger area.

How Much Electricity Does a Patio Heater Use?

This will depend on its wattage, which can usually be found somewhere in the literature. Some heaters feature different intensity levels, and will list the watts used by each level somewhere as well (the user manual might be your best resource).

If you would like to find out how much you’re spending every hour your heater is on, this can be done with some quick math: first, you divide your heater’s watts by 1,000, to obtain the kilowatts. Then, you multiply this number by the going kilowatt rate in your area, which you can find in your monthly energy bill. Let’s say, for example, that your heater is 2000W. Per your energy bill, you pay 12 cents per kilowatt consumed. The math would go like this:

2000/1000 = 2kW

2 x .25 = .50

Your cost would be of 50 cents per hour. You can then multiply this by the number of hours you use (or want to use) your heater, and you obtain your cost per session. If you were to leave the heater on for 8 hours, that would cost you 4 dollars.

Patio Heater Safety and Comfort FAQs

Comfortable backyard patio area near a pool

Can Electric Heaters Cause Carbon Monoxide Poisoning?

However uncalled for the question may seem, it’s still a valid one: we will be using our heater near our friends, family and pets, and thus we want to leave no stone unturned. We’ve mentioned this in passing a few paragraphs back, it’s time to discuss it more in depth.

Carbon monoxide is generated whenever there is combustion, i.e. a fuel such as gas or wood is burning. Electric heaters do not rely on any sort of combustion for providing heat: rather, they provide warmth by running an electric current through a coil that stretches within. In the words of Johns Hopkins, “[e]lectrical space heaters pose no danger of carbon monoxide poisoning, unlike those that burn fuels, such as kerosene”. If people feel dizzy or ill near an electric heater, it’s not poisoning; it means the air got too dry, and there are easy ways to mitigate this.

  • Keep good ventilation. This will freshen up the air constantly.
  • Place a bowl of water at a prudent distance. It will help preserve humidity.
  • Don’t overuse the heater. Keep the potency only to the level you need to make you comfortable, and don’t leave it running for longer than necessary, so as to help maintain moisture.

Can Wall Heaters Catch on Fire?

Technically, they can. The good news is, it’s not hard to mitigate this risk.

One of the more common reasons why a wall heater may catch on fire, is because of overload. Heaters draw hundreds of watts through their cord; if plugged into an extension cord that is too weak or too long, or connected to a multi outlet, the tension will cause overheat and, possibly, a fire. To prevent such problems, plug your heater directly into the outlet without any extension cord in between. If this is not possible, it’s better to let a professional perform the installation; they will know what cord to use so it is safe and won’t overheat.

Aside from the cord, remember to mind the distance between the heater and everything else. Keep furniture and anything potentially flammable a good 3 feet away from the heater. Whenever the cold season begins, check if something might not have been moved too close to the unit while it was not being used; if anything is too close, correct it before starting the heater.

If a fire develops, do not use water! Instead, turn the switch off at the circuit box to interrupt the flow of power. If you use an extinguisher, remember to make sure it is class C; it doesn’t hurt if yours is for multiple fire classes, either.

Do Patio Heaters Attract Bugs?

They do, and to varying degrees. Some bugs are drawn to light, some others are drawn to heat; one particularly pesky variety—mosquitoes—responds to carbon dioxide like fruit flies to sugar, which might help explain if you and your family have turned up with plenty of bites after being around the propane heater.

Using an infrared heater greatly mitigates most of these lures for insects; if you’re a fan of your propane or gas flame, a bug zapper might help with the mosquitoes at least.

Are Outdoor Heaters Bad for the Environment?

Depends on your definition of ‘bad’, and on the heat source you’re using. Here’s a breakdown by category.

Backyard greenhouse

1. Electric

Minimal impact while operating, as there are no emissions. They do draw hundreds (if not thousands) of watts in order to provide heat, so they do put some additional strain on the grid and on energy generation. Most heaters are made disposable, too, meaning they can only be thrown away after their filaments wear out. That’s extra space in a landfill.

2. Gas or Propane

These are a source of carbon monoxide, which is why it is so important to use them with adequate ventilation. Small though they may be, these emissions do add up at a time when air quality is a prominent concern.

3. Wood

Fire pits, stoves and similar heat sources have the advantage of running on a renewable fuel. However, they are also the worst when it comes to emissions. Smoke can become such a problem, some areas will even declare burning bans periodically, which can prevent you from using even your BBQ grill.

As of this writing, there is no true eco-friendly heater; all of them will have an impact on the environment, one way or another.

Final Thoughts

Winter no longer has to be a deterrent whenever you want to enjoy your patio. All it takes is a heater appropriate for your space, your taste, and your fuel preferences. Just remember to take into account your square footage, implement your prevention measures, keep an eye on your heater when it’s running—and all there is left to do is to have a good time!