If you have been camping with your favourite camping stove for a while now and noticing yellow flames instead of the usual blue flames on the burner, your stove is not burning ‘clean’. There are a few reasons for yellow flame on camp stoves (or any stove for that matter), and today, we will learn how to fix yellow flame on camp stoves.
First, the reason you have a yellow flame on your stove is due to an incorrect fuel/air ratio. You are burning more fuel in less air due to which some of the fuel is burning incompletely resulting in yellow flame. The reason for the incorrect fuel ratio is normally clogged burner vents.
Let’s discuss things in more detail.
Why you get yellow flames on stove?
All common fuel gases including Propane, Btunane & Methane burn blue when they get excess air and combust completely and properly. You can say that blue flame is an indicator that your stove is working at peak efficiency.
But when you see a yellow flame, you should be worried as things are not as good as they should be. Something in your gas line is depriving oxygen supply to the fuel, and therefore it is burning incompletely.
When fuel gas burns in less oxygen, it produces soot – very fine carbon particles. These soot particles then get heated in the flame and become incandescent and give off yellow/reddish light. These incandescent soot particles are actually what makes the flame yellow toward the top.
There can be multiple reasons for the yellow flame on the stove. Let’s discuss a few common ones below.
1. Leaked seals
As we discussed the cause of yellow flame i-e incorrect air/fuel ratio, one of the first things that you should check is leaked seals on all connectors. Especially when your hose and connectors are old and have been in use for a long time, there is a chance that one or more of them are leaked.
Also, check your hose for any cracks and raptures. Being in the sun outdoor for months, the flexible hose becomes brittle and develops a crack. These cracks and leaks reduce the pressure of fuel that is reaching the burner assembly, and you get an incorrect air/fuel ratio.
This is not the most common reason for yellow flame but as it is easier to check, you should do this first before disassembling your stove for further inspection.
2. Clogged burner
Now, this one is the most common reason for old stoves giving off yellow flames. The burner assembly in your stove is finely tuned to produce a precise mixture of air and fuel. This correct mixture is called the Stoichiometric ratio.
There are multiple reasons for your burner assembly to get clogged. A few of them are;
- Corrosion: When your stove burner heats and cools for years, the metal parts corrode easily. You can actually see the corrosion on the burner head. These corroded particles then fall off from the burner into the void below, clog the airways, and block the air supply to the fuel.
- Foreign objects: Since your camping stove is primarily used outdoors, there is a good chance that any foreign objects clog the airways. These can be dead insects or dirt particles or anything else that might have gotten into the burner assembly through the air intakes.
- Oil and grease spills: We all love a well-done beefsteak during our outdoor camping, they often get the burner assembly clogged. The oil and grease, along with meat particles, can slip inside the airways, jam the flow of air and disturb the air/fuel ratio.
3. Damaged / Misaligned fuel nozzel
When you look at your gas burner assembly, you will see a nozzle right next to the burner head. It is also called an orifice since it has a finely tuned pinhole that lets the correct amount of gas needed for proper burning. This high-velocity stream of fuel gas emitting from the nozzle creates a low-pressure vacuum area in the venturi section that sucks in air through the air inlets (see the diagram below)
Sometimes, due to the rough handling of the stove, this assembly gets misaligned, and the high-pressure stream cannot properly create the vacuum that sucks in air. When this happens, we deprive the fuel of the correct amount of air, and hence the stove burns yellow in low oxygen.
4. Incorrect nozzle Jet
If you recently changed your nozzle jets and started getting a yellow flame, you probably installed the wrong gauge nozzle.
Every fuel has its own nozzle orifice fined tuned to provide the correct Stoichiometric ratio. Propane orifices are very small compared to the ones used on natural gas stoves. If you install an incorrect nozzle, you might end up getting a yellow flame. That’s the reason you cannot use natural gas stoves on propane without switching to correct nozzles first.
5. Incorrect fuel type
Different fuel requires a different amount of air or oxygen to burn properly. The amount of oxygen required to burn a single molecule of fuel completely is dependent on the molecular structure of each fuel. The following table gives you an overview of the top 3 stove fuel sources and the correct fuel ratio for each.
| Fuel | Molecular structure | Air to fuel volume ratio |
|---|---|---|
| Butane | C4H10 | 31:1 |
| Propane | C3H8 | 24:1 |
| Methane | CH4 | 10:1 |
As you can see, each fuel type requires a different amount of air to burn completely. Each stove has been designed to work on one specific fuel type, and you cannot interchangeably use one stove on different gases. For example, Butane needs the most amount of air to burn. If you try to burn Butane on a natural gas stove, the stove will not provide enough air to burn completely, and you will get a yellow flame.
Is yellow flame bad?
Yes, a yellow flame on your stove is a sign of inefficient fuel burning due to an underlying issue with the burner assembly. Here is why it is bad.
Burns more fuel
A yellow flame is a sign of inefficient burning. It burns more fuel to provide the same amount of energy as a blue flame would. This is because not every molecule of the fuel burns completely to release its full energy. Due to lack of enough oxygen, some part of the fuel does not burn and convert to soot (fine carbon particles).
Produces less heat
A yellow flame burns at a lower temperature compared to a blue flame. The following table indicates the temperature at which yellow and blue flame burns for each fuel type. Low-temperature burning means your food will take more time to cook on a yellow flame than a blue flame.
| Fuel | Blue Flame Temperature | Yellow Flame Temperature |
|---|---|---|
| Butane | 1970 °C (3578 °F) | ~ 1000 °C (1832 °F) |
| Propane | 1980 °C (3596 °F) | ~ 1000 °C (1832 °F) |
| Natural Gas | 1960 °C (3560 °F) | ~ 1000 °C (1832 °F) |
Carbon monoxide poisoning
When fuel is burned in the presence of oxygen, it converts to carbon dioxide (CO2) and water. Both CO2 and water are harmless substances. But when the same fuel burns in the absence of enough oxygen, instead of converting to CO2, it gives off carbon monoxide (CO), which is poisonous when inhaled in high quantity.
Carbon monoxide is the prime cause of death in heater related incidents around the world. When burned in a closed quarter, any heater or stove will produce CO, which accumulates in the room and induce sleep leading to death.
A yellow flame is similar in nature as it indicates fuel burning in a low oxygen environment leading to the production of poisonous CO. However, if your stove is placed in an open area, the risk of CO accumulation is less likely.
Produces soot
If you have been dealing with a yellow flame stove, you might have noticed a black layer on your utensils. This is a soot deposit. Soot is the byproduct of incomplete burning of fuel in a low oxygen environment.
As discussed above, the color of the yellow flame is these soot particles that heat up and give off yellow light.
How to fix yellow flame on camp stove?
Now that you know the major causes of a stove with a yellow flame, it’s quite easy to fix it. If you are not sure what is the exact reason for your yellow flaming stove, start with the easiest fix and move down the line.
Inspect any leaks: First of all, inspect all the joints and hoses for any sign of cracks or deterioration. If you can’t see any damage, connect the fuel tank to the stove, turn on the tank valve, spray some soapy water on all joints, and see if any bubble grows. A bubble will indicate a possible leak area. Fix any leaks and check if that solved your problem.
Clean your burner assembly: The next step is to clean your burner assembly to remove any corroded particles, clogged areas and any other hindrances that might block the normal flow of gas and air. In most cases, this should fix your problem.
Check out the below video to learn how to clean your dirty burners and stove in general.
Use correct nozzle jet: The wrong orifice size on your nozzle jet can also cause an incorrect air/fuel ratio. If you recently changed your nozzle jets and are getting yellow flame, this could be the issue. Check out your stove manual, find out the correct part number, and install only that for optimum performance.
Inspect your burner assembly for damages: See if your burner assembly has any visible dents, holes etc that could potentially mess up your air/fuel ratio. If you find any damage, it’s probably time to install a new burner and get rid of the old one.
Use the right fuel: You cannot use your stove on different fuels without changing your nozzle jets and pressure regulator. If you switch to high-pressure fuel without a proper modification to your burner assembly, you will get the yellow flame. Always use the right fuel.
Conclusion
A yellow flame stove is a sign of dirty burning. The reason can be incorrect air/fuel ratio due to dirty burner, clogged assembly, incorrect fuel type or nozzle jet. I hope the information and tips in this article will help you get a clean-burning stove.
FAQs
Is yellow flame dangerous?
A yellow flame is dangerous in a closed room because it indicates an incomplete burning of fuel which produces carbon monoxide. CO is a poisonous gas and if inhaled in large quantity could result in death.
Are yellow flames dirty?
A yellow flame is an indication of a fuel burning dirty. It produces soot and carbon monoxide which is poisonous.
What is the hottest fire color?
The hottest fire burns with dark blue color at around 14000 °F.
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