Why Is Your Gas Grill Flame Yellow?

Troubleshooting Tips and Possible Solutions

Big Yellow Flame

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If your grill is showing large yellow flames instead of a blue flame with yellow tips, there is something wrong. A yellow flame can be a sign of failed components or simply an adjustment problem. This can cause low heat, uneven heat, a build-up of soot on foods, and just bad grilling in general. See how to work through several problems to fix your grill.

Yellow Flame on a Gas Grill Signals a Problem

The flame on a gas grill should be blue with yellow tips. If you have large, uneven yellow flames, then something is wrong with your grill. It could be several problems that may or may not require replacing parts of your grill. We are going to go through these problems from the easiest to the hardest and hope your grill is fixed before you have to spend any money.

Checking for a Stuck Regulator

Often, the regulator on gas grills gets stuck. This causes low gas pressure. You will notice that your grill isn't getting hot. To fix a stuck regulator follow these steps exactly:

  1. Turn off the gas at the propane tank.
  2. Disconnect the gas line from the tank.
  3. Open the grill lid.
  4. Turn all control valves to high.
  5. Wait for about a minute.
  6. Turn all control valves to off.
  7. Reconnect the gas line to the tank.
  8. Slowly turn on the gas at the tank.
  9. Light the grill normally.
  10. Your grill should now heat normally.

To keep the regulator from sticking again make sure that you turn off the control valves first, then turn off the tank valve. Always open your tank valve slowly. If your gas grill still has a yellow flame and the temperature is still low, you will need to replace the regulator.

Burner Adjustment

A yellow flame can be caused by a bad mixture of gas and air. This can be typically fixed by adjusting the burner air intake. To adjust the burners on your gas grill, you are probably going to have to get under or inside the grill. The adjustment point is where the burner connects to the grill manifold (usually right behind the control valves). Gas grills come in a number of configurations, and you may need to consult your manual to find the adjustment screw. This screw holds a sleeve in place. This metal sleeve is slotted and when the screw is loosened you should be able to rotate it. Remove the cooking grates and barrier over the burners so you can clearly see the flame.

With the grill off and cool, loosen the screw and rotate the adjustment sleeve. Tighten the screw and relight the grill. Wait a minute for the flame to settle in and see if you still have a yellow flame. If you do, repeat the process until the yellow is almost eliminated. A good flame is predominately blue but may have yellow tips. Once you have that burner burning mostly blue repeat for the other burners.

Cleaning the Burners

If this doesn't fix the yellow flame issue, you might have debris inside the burners or burnt-on grease or food on the outside of the burner. This can block the ports (holes running along the side of the burner). This forces the gas out of the unblocked holes causing an excess of pressure that leads to a yellow flame. Inspect the burners to make sure they are not damaged or rusted. If they are, you will need to replace them.

You might be able to gently brush the outside of the burners to remove the debris, but chances are you will have to remove the burners entirely and clean out the inside. This can be a simple or complicated task depending on the build of your grill. You will want to consult a manual to see how all this goes together. When removing, be gentle with the burners. You don't want to damage a perfectly good burner.

With the burner out use a thin wire or pipe cleaner to remove all the debris from inside the burner. If you wash the burner or use water on it, make sure you dry it completely before putting it back on the grill. You might want to take a little preventive measure and coat the outside of the burner lightly with cooking oil. Make sure not to block the ports and choose an oil with a high smoke point. With the burners clean, put your grill back together and check the flame. 

Alignment Problem

If you still have a yellow flame, the problem might be an alignment problem. The burners, control valve or manifold might not be lined up right to let the gas flow through properly. The gas flow should be a straight line through all the parts. Examine the entire flow of gas to make sure that all these parts are all in the right alignment. While doing this examination make sure that there are no cracks or holes in any of these parts. Damaged parts will need to be replaced.

Do You Still Have a Yellow Flame?

If you've done everything up to this point and still have a yellow flame problem, answer this question. Are you experiencing a yellow flame with all the burners or just one burner? If it is all of the burners, then you most likely have a bad regulator. You will need to replace this part. If the problem is with one burner, then it is either the corresponding control valve or with the manifold. These parts might be defective and need to be replaced, or they might be clogged. You can try removing the control valve and manifold to clean them out. This might solve the problem, but if it doesn't, you can try replacing the control valve, or decide if the value of your gas grill is worth the expense of more repairs.