Guide To Fire Pit Burners
A fire pit burner is the heart of a gas fire pit, providing the warm glow of natural flame without the hassle of wood.
Whether you’re replacing a damaged fire pit burner, building your own DIY fire pit or table from scratch or researching the best models before making a purchase, we’ve got you covered. Here’s what you need to know about fire pit burners.
What Is a Fire Pit Burner?
At the heart of any gas-fueled fire pit is the burner, the element that determines flame pattern and size.
How Do Fire Pit Burners Work?
Essentially, fire pit burners are metal tubes perforated by tiny holes. Gas fuel feeds into the tube and is distributed evenly, escaping through the holes. An ignition system creates a spark or flame. The gas coming out of the burner combusts, creating an even array of natural flames.
Because fire pit burners are often buried under lava rocks or glass, their function and design is often obscured. For a more visible example of this process in action, take a look at a gas burner on a grill or stove. Both employ the same process of supply, distribution and ignition.
Variations on the basic burner involve size, shape, material and the addition of gas nozzles. But before we get to the actual burner, we need to talk about fuel.
Propane vs. Natural Gas
Gas fire pits are fueled by natural gas or liquid propane. The choice of gas doesn’t impact the burner itself. Rather, the difference is in the delivery system connecting the source of fuel (a natural gas line or propane tank) and the burner.
When purchasing a burner, make sure it’s appropriate for your fuel of choice, or buy an adapter kit to convert it to that fuel. Many burners come in propane or natural gas models or include an adapter kit.
Plate or pan
The type of fuel also impacts another element of the fire pit: the burner plate or pan. This is a flat metal disc seated beneath the burner. Pans have a raised outer lip, while plates, naturally, are flat. For our purposes, we’ll use these terms interchangeably.
Natural gas fire pits generally don’t require a pan, but most propane fire pits do. Some burners are sold with an attached pan.
Fire pits need a pan because propane is heavier than air. If propane settles at the bottom of the fire pit, it could ignite all at once and create a large explosion. The pan holds it closer to the igniter so it doesn’t filter to the bottom.
Propane also needs a mixture of air to burn without generating soot. Propane fire pits usually have an air mixer in the supply line. Because natural gas is lighter than air and burns cleanly, and it doesn’t require a pan.
Many DIYers opt for pans in natural gas fire pits as well because pans make it easier to fill the pit with decorative elements such as lava rocks or fire glass. They also act as a lid, allowing easy access to the bottom for maintenance and cleaning.
If you’re using a burner pan, keep in mind that they can also trap water, and should have weep holes or some other way to shed water. If too much water builds up in the pan, it can seep into the burner holes.
Types of Fire Pit Burners
Besides propane vs. natural gas, there are a number of variations on the basic fire pit burner.
Standard fire pit burner
A standard burner features a series of small holes drilled or punched into it to allow gas to escape. Punched-hole burners are more economical, but the punch process may leave dimples around the hole, allowing small amounts of water to pool. Manufacturers of drilled burners typically don’t shave off the resulting burr, so it acts as a shield against water penetration.
Nozzle fire pit burner
Nozzle fire pit burners are easily distinguished from standard burners. Instead of releasing gas through a simple hole on the burner surface, these burners are ringed with metal nozzles that resemble the tips of a pressure washer. These nozzles use an air intake to boost the flame size.
Nozzle burners may be brass, stainless or a mixture of the two. They go by different names depending on the manufacturer. Examples include Bullet Burners from Outdoor Plus or Crossfire by Warming Trends. Performance varies, but they produce dramatically larger flames while using significantly less gas.
Burners come in multiples shapes and sizes. Some popular shapes include linear (H, T and U), round, square and custom-designed. Larger burners generate more heat, and some shapes provide a more uniform flame field. But for the most part, shape is a matter of personal preference.
Fire pit burners are rated in Btus (British thermal units). Btus indicate how much heat the flames give off. The right amount will depend on your personal preferences, the gas supply to your home (for natural gas) or size of your propane tank.
Typical fire pits fall in the 80,000 to 120,000 Btu range at maximum flame height. Most gas-fueled fire pits are adjustable.
Those 20-pound propane tanks normally seen on gas grills can deliver about 430,000 Btus for one hour. So if you have a 100,000 Btu fire pit burner, a 20-pound propane tank would give you a little more than four hours of burn time at full flame height.
Burners are typically stainless steel or brass. Stainless steel is significantly less expensive, but brass is more resistant to weather and high temperature and lasts longer. On the other hand, stainless tubing bends easily. If you want curved or custom shapes, stainless provides far more options for customization.
How To Choose a Fire Pit Burner
Are you looking for a new off-the-shelf fire pit, replacing a damaged burner, or creating a custom DIY fire pit?
Shopping for a new gas fire pit
Opt for a model with a brass burner if you plan on using it for many years, or a nozzle burner if you want dramatic flames. Otherwise, simply decide whether you want a natural gas or propane model, and the Btus you’d like.
Buying a replacement fire pit burner
In this case, try to match the existing model as closely as possible. Size and shape are usually determined by the fire pit, so there’s not a lot of leeway there. You may want to upgrade to a brass burner or a nozzle burner. But otherwise, sticking to the existing burner type is the safest best.
Building a DIY gas fire pit
This is the area where you’ll have the most freedom, and the greatest number of choices. Take your time to make sure you’re buying the proper equipment for your type of fuel.
When it comes to the size, try to maintain at least three inches between the edge of the burner and the outside of the fire pit. Some burner manufacturers have slightly different specs, but three inches is a good guideline to ensure the flames have sufficient air without spilling out of the fire pit enclosure.