Gas Patio Heater Buying Guide

Despite their space-age designs, gas patio heaters are really very simple devices. Gas from the cylinder is piped up through a hose that runs the length of the heater. The gas is ignited in the burner at the top of the heater and produces a warming flame. In operation, gas patio heaters are very similar to a gas hob or camping stove.

Although the setup of a gas heater is very simple, there are a few “clever bits” along the way that help the heater function safely and effectively.

Gas Regulators

The first of these is the gas regulator. Gas regulators are required in all gas applications. The regulator connects the gas hose to the cylinder and controls the pressure at which the gas is released. There are many different kinds of regulator designed to convert between different levels of pressure, so it’s important to use the right kind of gas cylinder for your regulator, and vice versa. Butane and propane need to be released at different levels of pressure, so you can’t use these types of gas interchangeably unless you also switch the regulator. Most gas patio heaters come with a propane regulator, because this is the most popular form of LPG for outdoor applications.

Ignition

Always read the manual before attempting to light your patio heater. Like gas hobs, different gas patio heaters come provided with different forms of ignition technology. Today, very few gas patio heaters still require matches to light and are instead equipped with a mechanical piezo ignition key, such as those found in cigarette lighters, which produces electric sparks.

Some patio heaters combine the electronic ignition key with a pilot light. Unlike old-fashioned standing pilot lights that are left on all the time, modern pilot lights that work with an electronic ignition are only lit when you start using your heater. If your patio heater has a pilot light, the first setting on its control dial will be marked “pilot”. Holding the dial down on this setting will release a flow of gas into the pilot light burner, which is then ignited by the electronic ignition. Once the pilot light is lit, you can turn the dial up to open a flow of gas to the main burner. The gas is then ignited by the pilot light.

The main reason why some patio heaters have pilot lights is because they provide a higher energy ignition source which can make it easier to light the main burner. However, some manufacturers have taken care to engineer out the pilot light and ensure that the piezo ignition key is powerful enough to light the main burner directly. This effectively cuts out the middleman and usually makes ignition a faster process.

Thermocouples

You may find that you need to wait for up to 30 seconds or more for your pilot light or main burner to stay lit. This is because of a safety feature called a thermocouple. Thermocouples are designed to prevent gas leaks in the event the pilot light or burner flame goes out. The thermocouple keeps the gas valve closed unless it exceeds a certain temperature. If the flame goes out, the thermocouple will automatically shut the valve. This is an essential safety feature designed to prevent dangerous build-ups of gas, but it does mean that you will need to wait for the thermocouple to warm up before the gas flame can stay lit.

The flame produced by a gas patio heater transfers heat in the same way as a fire: predominantly through radiation. This is the most effective form of heat transfer for use outdoors because it heats directly, regardless of the temperature of the air. Convection heaters which heat by warming the air are useless in outdoor spaces because the warm air will always escape to cooler locations.

Like an open fire, a basic gas patio heater will radiate heat in all possible directions: outwards towards the surrounding people and upwards into the sky. More efficient gas patio heaters come equipped with a reflector at the top of the heater which focusses the heat back down to where people are gathered. On some models, this reflector can be adjusted to target heat in a particular direction, allowing you to maximise the effectiveness of the heat produced.

The range of the heat span produced by your gas patio heater can be adjusted via the heater’s control knob. Turning the gas flow to its highest setting will maximise the heater’s output and heat the largest possible area. The total maximum heated area will depend on a range of factors, from the type of gas cylinder used to the size and position of the burner. A 13kW free standing gas patio heater will typically heat an area of between 15 and 28m2.

LPG stands for liquefied petroleum gas. LPG fuels are mixtures of flammable hydrocarbon gases which are stored as liquids in pressurised containers. They return to a gaseous state when they are released from their containers, at which point they can be ignited to provide power for heating and cooking. LPG fuels are compact and easy to transport, which is why they are commonly used as a power source for homes in remote locations that do not have access to plumbed natural gas. Propane and butane are two of the most common LPG fuels.

Propane and butane are two of the most well-known LPG fuels which are commonly used in household and camping applications. In their pure forms, propane and butane are chemical compounds with the formulas C₃H₈ and C₄H₁₀ respectively. Propane cylinders are normally red, whilst butane cylinders are blue. The most significant difference between propane and butane is their boiling points. Whilst butane becomes a liquid at just -1 °C, propane must be cooled all the way to -42 °C before it liquefies. This means propane mixtures must be kept at much higher pressures than butane mixtures in order to stay a liquid at room temperature.

Technically speaking, the gases you find inside commercial gas cylinders are not pure propane or butane. The nature of the distillation process is such that it is much simpler to use mixtures of gases made up of mostly propane and mostly butane. This is perfectly normal, with the mixtures standardised to liquefy at the same temperature.

In terms of heat output and burning efficiency, there is very little difference between propane and butane. However, it is almost always better to use propane in gas patio heaters because of its lower boiling point. Whilst propane-fired patio heaters will function normally all the way down to -42° C, butane will struggle to vaporise when the temperature gets close to zero. This means that you will struggle to light your patio heater if you ever want to use it on a frosty day.

Some patio heaters will specify that they must be used with a certain type of gas – usually propane. This may be because they come pre-fitted with a propane regulator.

When shopping for gas cylinders, you may find a third option called “patio gas” advertised. In most cases this is not actually a third option but a re-branding of propane – testament to the popularity of propane for outdoor applications.

You may find however that propane and patio gas cylinders come fitted with different valves. This means they will not be compatible with the same gas regulator – the connection between the cylinder and the heater. You may find that propane cylinders require a screw-on gas regulator, whilst patio gas cylinders require a clip-on gas regulator. Most gas patio heaters come pre-fitted with a 27mm clip-on gas regulator, so you may find your choice limited to patio gas propane. Always double-check with the gas cylinder retailer that their cylinders will be compatible with your appliance.

Why do different gas cylinders come with different valves? On the one hand, it’s a safety precaution, to make it harder for users to inadvertently use, for instance, a propane regulator with a butane cylinder. More cynically, the use of different valves can help gas cylinder manufacturers push their customers towards more expensive ranges of cylinders. Using different valves forces customers to purchase whichever cylinders are compatible with their appliances. The only other option is to replace the gas regulator supplied with the heater.

Most patio heaters can be used with either butane, propane or patio gas cylinders, but the different valves used and different levels of pressure required mean that you will need a different gas regulator depending on what fuel you use. It is usually easiest to choose your gas cylinders based on the regulator supplied with the heater – but you can change the regulator if you want to use a different type of cylinder.

Gas regulators do two important jobs to control the flow of gas to the burner. Firstly, they decrease the pressure from the high level sustained inside the cylinder to the low level required by the burner. This ensures the patio heater cannot burn too fiercely. Secondly, they keep the flow of gas to the burner at a constant pressure. This ensures the heater burns steadily and does not falter with the changing pressures inside the gas cylinder.

Gas regulators vary in two important ways: first, the level of pressure they are designed to output, and second, the type of valve to which they connect.

Butane and propane cylinders require different regulators because the gases need to be kept at different levels of pressure to burn at the same rate. Butane regulators for low pressure appliances such as patio heaters provide an outlet pressure of 28mbar, whilst propane regulators have an outlet pressure of 37mbar. Butane and propane cylinders also have different valves, which makes the regulators physically incompatible. You will also find that different brands of propane gas use different valves, so it’s doubly important to check the compatibility of your regulator.

Most gas patio heaters come fitted with a clip-on propane regulator. If you want to use butane with the heater, you will need to replace the propane regulator with a butane regulator. Similarly, if you want to use propane cylinders with a screw-on valve, you will also need to change the regulator.

Always check that your heater is compatible for use with your intended cylinder before changing your regulator. Always check with your gas cylinder supplier to make sure you choose the right regulator for the cylinder you want to use.

Once you’ve worked out what type of cylinder you want to use with your patio heater, you’ll be able to choose from a range of bottle sizes. Although larger bottles are heavier, they can also be more convenient, because they allow you to use your patio heater for longer before replacing the cylinder. Larger bottles almost always work out more economical because the associated costs of bottling, transport and storage will work out cheaper for one large cylinder than for several small cylinders.

Some gas patio heater manuals specify a recommended cylinder size, or range of sizes. 13kg cylinders are usually ideal, and many free-standing gas patio heaters with compartments for housing the cylinder are designed to cater for this size.

If you’re planning to use your patio heater on a regular basis, you will need to store a supply of gas cylinders. To do this safely, you must adhere to all instructions provided by your supplier. The bottles must be stored in an upright position away from sources of heat and ignition. Gas cylinders must be stored outdoors, in a covered but well-ventilated area free from direct sunlight and extremes of temperature. They must never be stored indoors.

A typical 13kW gas patio heater will burn gas at a rate of 1230g/h when used on its maximum setting. This means a 13kg gas cylinder will last for about 10 hours of use – or significantly more if you use the heater on a lower setting. A 13kg propane cylinder costs about £30, so you’re looking at running costs of about £3 per hour, or £2 per hour if you use it at a lower setting.

Gas patio heaters, just like electric patio heaters, distribute heat via radiation. This is the same form of heat given off by the sun. Radiant heat from the gas flame warms people and objects directly, without heating the air. This is the most efficient way of heating outdoors. In comparison, convection heaters that heat the air are very inefficient outdoors because the warm air is instantly lost as it disperses to cooler locations.

Some sites claim that gas patio heaters are less efficient than electric because they disperse heat in all directions, rather than direct it to where people are sitting. This may be true of very basic flame heaters which radiate heat from all possible angles. However, most modern gas patio heaters are fitted with a reflector above the gas flame which re-focusses the heat moving upwards and directs it down to the surrounding area. Some heaters are even fitted with an adjustable reflector which allows you to point the heat in different directions – a great way to make sure none of the heat generated by your gas patio heater is wasted.

Gas is a fossil fuel which produces carbon dioxide when burnt. This is true of all forms of gas. Whilst there are some arguments that the propane used in gas cylinders is cleaner burning than household gas, the gains of this are largely irrelevant because the distillation process through which propane is extracted also produces methane and the other gases which make up plumbed natural gas.

Electric patio heaters have more of a claim to eco-friendliness because they do not directly produce any carbon emissions. An electric patio heater run off green electricity provides completely carbon neutral heating. However, most electric patio heaters are powered by mains electricity, which is still predominately generated in power stations which burn fossil fuels, so in most cases there is no real difference between the environmental impact of a gas and electric patio heater.

The bottom line with gas patio heaters is that they’re not in and of themselves inefficient – but any kind of outdoor heater is a bit of a luxury. However, from an environmental perspective, the indulgence is on a par with an evening spent watching TV or playing on a games console. If a little bit of heating on those colder nights makes the difference between you getting outside and enjoying your garden or spending yet another night indoors – then we reckon it’s worth it.

Gas patio heaters are carefully engineered to minimise all risk associated with gas combustion, from preventing gas leaks to limiting the scope of the flame.

No naked flames

Despite the dramatic display of some flame patio heaters, you won’t find a gas patio heater for domestic use that actually has a naked flame. Flame patio heaters typically have their flame encased in a protective quartz glass tube, whilst heaters with a discrete, hob-style burner combine this protection with a shielding reflector at the top of the heater. Flame and table-top heaters often come with the additional protection of a metal grill which makes it harder to touch the hot glass accidentally.

Electronic ignition

It’s very rare to find a gas patio heater that you have to light with a match. Modern gas patio heaters all come equipped with a mechanical piezo ignition key, just like those found in cigarette lighters. This makes lighting the heater much easier and eliminates the risk of burnt fingertips.

Anti-tilt mechanism

Most modern gas patio heaters come with an anti-tilt mechanism built into the burner. This mechanism responds to movement and extinguishes the flame if the heater tips or falls. This means the heater is unlikely to cause damage if it is knocked over or blown over in high winds.

Gas leak prevention

All gas valves are fitted with a thermocouple which automatically shuts off the gas supply if the heater flame is extinguished. This prevents gas leaks in the event the flame is blown out on a windy day. Thermocouples work by responding to temperature. When cold, they keep the gas valve shut. When the flame is lit, the thermocouple quickly heats up and keeps the valve open. As soon as the flame is extinguished, the thermocouple will go cold and automatically close the valve. Thermocouples are also known as flame failure devices.

Gas patio heaters can only become dangerous if used in an irresponsible manner. To prevent accidents, make sure you follow all instructions provided in your patio heater manual.

Use

It’s important to follow all instructions provided in the manual whenever you use your patio heater. It is particularly important to check for leaks when assembling the heater and attaching the cylinder for the first time. This is quick and easy to do with a soapy water solution. Any gas leaks will be made obvious by bubbles forming in the solution. Never leave a burning patio heater unattended and do not use in high winds.

Location

Never use a gas patio heater inside, or in a covered or poorly-ventilated area. Most manufacturers define a well-ventilated area as one with a minimum of 25% of the surface area of its perimeter open. This means they are suitable for use underneath some outdoor structures, but only if the structure has been designated suitable for use with patio heaters by the manufacturer. It goes without saying that you will need plenty of clearance between the top of the heater and the canopy above.

Storage

When you’ve finished using your gas heater, make sure you close the gas valve and disconnect the cylinder. Most gas heaters can be left outside, provided they are securely installed so they can’t blow over, however you may want to use a patio heater cover to preserve the paintwork.

If the heater is going to be unused for a longer period of time, for instance over winter, you may want to put it in a garage or shed as further protection from the elements. However, you will need a separate, outdoor storage area for your gas cylinders. Gas cylinders must never be stored indoors.

Maintenance

Whenever you use your gas patio heater, you should make a habit of checking for leaks and damage to the burner, regulator and gas hose. It is also a good idea to check for debris in the burner before lighting the heater. Gas patio heaters should be cleaned with a soft, moist rag. Do not use corrosive or combustible cleaning products to clean your heater.

Gas patio heaters should be serviced every 100 hours of use or once per year, whichever comes first. Services and repair work must be carried out by a qualified gas technician.

One of the great advantages of gas patio heaters is that, unlike electric patio heaters, they can usually be installed DIY. Electric patio heaters have to be wired into the mains, which is a job for a professional electrician, but most gas patio heaters just need assembling and attaching to a gas cylinder. Occasionally, you will find a gas patio heater that specifies that it needs assembling by a qualified gas technician, but this is usually only the case with heaters sold to the trade. Currently, all our gas patio heaters are suitable for DIY installation. Full information can be found on the product page.

Gas patio heaters are usually easy to assemble, supplied with all fittings, fixtures and a full set of instructions. Most gas patio heaters are also supplied with a gas hose and regulator, although in some cases you will need to purchase these separately. Where this is the case, full guidance on the type of regulator and hose required will be provided in the manual.

Assembly is usually just a case of piecing together the separate parts of the heater frame, fastening them in place with screws and bolts. Likewise, the reflector and cylinder housing are usually supplied as separate panels that need to be screwed together. If the gas hose is not already connected, you will need to attach it to the burner, run it through the central post and attach it to the regulator in the cylinder chamber. Then you will be ready to attach the gas cylinder and make final checks on the heater before using.

Assembly should require only basic DIY tools: a wrench, screwdriver and pair of pliers. A bottle of soap solution is also useful to help check for leaks.

Your gas patio heater and all its components will be fully tested for leaks before it leaves the manufacturing plant. However, to ensure that no damage has occurred during transit, you should thoroughly inspect the entire heater assembly, including hose, regulator, pilot light and burner, before using. You should check for obvious damage and perform a leak test to make sure no gas is escaping from the heater before it reaches the burner.

The best way to check for leaks is with a soap solution, made with one part liquid detergent and one part water. Apply the solution to the heater with a spray bottle, brush or rag. Open the gas supply to the heater and watch for bubbles. Any bubbles forming in the solution will indicate a leak. If the bubbles form over the connection between the regulator and the hose, or the hose and the cylinder, switch off the gas and tighten all connections. If you continue to see bubbles after all connections have been tightened, it may be your gas hose or cylinder are defective. Contact your place of purchase for further guidance and do not use the patio heater.

Keep your patio heater away from naked flames while leak testing. It goes without saying that you should never smoke while leak testing or operating your patio heater!

It’s important to keep the patio heater clean and free of debris. Obstructions in the burner, gas hose or cylinder compartment will interfere with the smooth operation of the heater. A blockage in the gas hose could have very serious consequences. Checking for blockages and removing any debris should be a matter of routine whenever using your patio heater. As a preventative measure, we recommend keeping the patio heater under a protective cover when not in use. This will help prevent the accumulation of leaves, insects and other outdoor detritus.

It’s also important to keep the heater’s surfaces clean. This will help prevent rust and will keep the heater looking its best. Use a soft, moist cloth to wipe down the heater’s surfaces whenever you feel necessary. Do not use combustible or corrosive cleaning products on your patio heater.

It’s good practice to check your gas patio heater for signs of deterioration at least once per month, or each time the cylinder is changed. If the gas hose shows any signs of cracking, splitting or is damaged in any other way, it should be replaced like-for-like with a hose of the same length and quality. The type of hose required will be specified in the heater manual, but if you are at all unsure, it’s worth seeking the advice of a qualified gas technician to make sure you purchase the right hose for your appliance.

The main reason you’d need to change the gas regulator is if you want to use the heater with a different type of gas cylinder. Most gas patio heaters come supplied with a clip-on propane regulator, but are also suitable for use with other types of gas, such as butane cylinders or propane cylinders with screw-top valves. You should never replace the regulator with any model other than those specified in the heater manual. If you are in any doubt what kind of regulator can be used with your heater, consult the heater retailer or speak to a qualified gas technician.

All things being equal, it is good practice to change the gas hose at least every 5 years and the gas regulator at least every 10 years.

It’s important to have your gas patio heater serviced periodically by a qualified technician. Your heater should be serviced annually or after every 100 hours of use, whichever comes first. This is to ensure your gas assembly is operating safely and efficiently, with no leaks and no risk of carbon monoxide production. The gas technician will remove, examine and clean all safety critical parts of your heater, clearing out any clogging deposits with a wire brush.

If you experience difficulties lighting your heater, you should be able to undertake basic troubleshooting using the advice in the heater manual. Common causes, which include loose connections, debris around the burner and an empty fuel cylinder, are easily remedied and will not require professional expertise. However, you should seek professional assistance if you experience any of the following problems:

• Burner lights but does not reach temperature
• Burner makes popping sounds during use
• Heater gives off smell of gas in conjunction with yellow tips to the flames

It’s very important that the area where you use your patio heater is adequately ventilated. In the event of a gas leak, escaped gases will quickly diffuse away in a well-ventilated area, and are unlikely to cause problems. However, a gas leak in an indoor or improperly ventilated area could have very serious consequences. This is because the gas will start to collect, risking gas inhalation and potentially causing explosions.

So, how do you know if your chosen area is adequately ventilated? A common rule of thumb is that at least 25% of the surrounding surface area must be open. So, in a square gazebo, at least one wall must be entirely open, to encourage air circulation and the evacuation of any residual gases.

There are clear reasons why you shouldn’t position your gas heater too close to other objects, structures and furnishings. Quite apart from the obvious fire risk, you also risk hampering the efficient flow of heat out from the heater. Most heater manuals will specify the minimum distance which should be maintained between the heater and any combustible materials. Typically, this will be up to 100cm from the top and sides of the heater.

We do not recommend using gas patio heaters under conventional awnings, tents or gazebos. You should only use purpose-built gazebos which specify their suitability for such applications.

It’s important to consider the people and animals who are going to use your garden before choosing a location for your patio heater. The burner can reach high temperatures, so it is important not to place the heater somewhere where it can be easily brushed against or knocked over. It is particularly important that the cylinder and hose assembly is kept out of the way where it will not be subject to accidental damage; the hose should not be trailed across pathways or under chairs.

Do not allow children or pets to play near the heater when it is in operation, and never leave the heater unattended while it is in use.

A pre-requisite for any gas heater fitting location is a secure, level floor that will provide a firm base for the heater. Gas heaters are not suitable for use on moving or unsteady floors, and therefore should not be used on vehicles or boats.

Many larger patio heaters can be bolted to the ground for extra security. This can be beneficial if you intend to use the heater in the same location every time. Permanently fitted outdoor heaters will benefit from a protective cover when not in use, to keep surfaces clean and prevent outdoor detritus from settling in the burner.

Umbrella style patio heaters are tall, free standing heaters that can exceed two metres in height. The base of the heater houses the gas cylinder, which connects to the burner at the top of the post via a long gas hose. The wide, circular hood at the top of the burner gives this style of heater its name, creating the comforting impression of a large, protective parasol. This hood is actually a reflector, which increases the efficiency of the heater by focussing heat which would normally escape upwards back down towards the people sitting around the heater.

Umbrella style patio heaters are elegant yet sturdy with plenty of scope for variation in design. The steel housing is available in a range of shades, from classic stainless steel to garden furniture green, from retro red to discreet black.

Pyramid style gas patio heaters, also known as flame heaters, make the gas burner into an eye-catching feature, with a long flame held within a quartz glass tube. Flame heaters have an exotic, extroverted feel, reminiscent of Hawaiian beach parties and pool-side bars. This makes them the perfect choice for restaurant terraces, pub gardens and waterfront bars. Giving off both heat and light, they’re sure to get the party started, evoking both the invigorating heat of warmer climes and the raw energy of the roaring flame.

Pyramid heaters are available in both large, free standing models and smaller table top versions.

Whilst free standing patio heaters make striking design features, well-adapted for heating large, open areas, some situations call for a more intimate heating solution. Table-top heaters are popular in back gardens and outdoor dining areas where all you want to do is heat a group of people sat around a table. These heaters are often scaled-down versions of larger, free standing heaters, designed to fit tidily in the centre of a table with plenty of space remaining for food and drink. The gas cylinder sits on the floor underneath the table and the hose is fed through the parasol hole. The heat produced is usually sufficient to heat those sat around the table, providing a cosy focal point for groups to gather around on cool evenings.