How To Adjust a Gas Fireplace’s Flame Color – Complete Guide

Many people nowadays own gas fireplaces due to their efficiency and low emission of poisonous gasses. However, did you know that there’s an ideal color for gas fireplaces’ flames, and you can adjust the color? 

Here’s how to adjust a gas fireplace’s flame color in 8 easy steps: 

  1. Locate your gas control knob and light the fireplace. 
  2. Allow the flame to burn for a while. 
  3. Adjust the damper. 
  4. Adjust the pilot flame. 
  5. Inspect your chimney or air vent. 
  6. Clean the fireplace. 
  7. Monitor carbon monoxide levels. 
  8. Change the fuel. 

This article is a complete guide on adjusting gas fireplace flame colors. So, keep reading to learn effective adjustment methods and add some color to your fireplace!

1. Locate Your Gas Control Knob and Light the Fireplace

If you’ve just installed a gas fireplace, you may be curious about the flame color. 

The natural color for gas flames is blue, indicating the complete combustion of natural gas or propane. However, gas fireplace manufacturers design the logs and other media to burn yellow flames (with red tips) to create a natural wood fire flame. 

So, if you’re curious to see what flame color your gas fireplace will have, you have to light it first. Before you do so, you need to locate the gas control knob. If it’s your first time, it can be daunting to know where the knob is, but the manual will guide you to where the controls are. 

Here’s how to light your gas fireplace: 

  1. Know where the gas control knob is. Check how to reach and operate the gas control knob from the owner’s manual. 
  2. Ensure that the gas valve is open. The shut-off valve keeps the gas away from the fireplace when it’s not in use. 
  3. Access the controls by removing the firefront or fireplace screen. They’re usually at the unit’s base but can also be at the middle of the burner. 
  4. Establish whether the gas control knob is at the “OFF” position. If it’s not, turn it off, and wait for a few minutes before you light the gas fireplace. 
  5. Turn the control knob from the “OFF” to the “PILOT” position. Turning the knob this way will light the pilot flame. You may also need to press a separate spark-ignition button before lighting the pilot (depending on your gas fireplace model). Also, let the dial remain depressed by pressing the button to allow the gas into the pilot. Then, release the dial 1 minute after the pilot is lit and turn it from the “PILOT” to the “ON” position. 
  6. Confirm if the pilot is lit. You can look at it from the logs (or coal) or the controls. The pilot will be part of the ignition system in most gas fireplaces. However, it can also be at the base of your unit. Restart the ignition process if the pilot doesn’t light or goes off. 

Here are two YouTube videos that demonstrate how to light a gas fireplace with a Piezo Igniter and a spark ignition button: 

2. Allow the Flame To Burn for a While

Once the pilot flame is lit and steady, you can replace the screen (or firefront) and also adjust the flame’s height. The first flame color you’ll observe will probably be blue, as it’s the default flame color of natural gas. However, it should start having yellow or orange tips after a few minutes. 

The yellow, orange, or red colors indicate incomplete combustion for other fireplace types. However, these colors will not portray any danger for a gas fireplace as they are simply there to mimic the ambiance of wood fires. 

After a couple of minutes, your gas fireplace’s flame should turn yellow (with red tips). However, if it remains blue, you’ll have to adjust the flame. 

3. Adjust the Damper

If your gas fireplace’s flame doesn’t change from blue to yellow, there’s probably excess airflow into your fireplace. You can regulate air circulation by closing the air shutter slightly. However, the damper should be open when lighting the fireplace for efficient ventilation. 

To close the air shutter, access the knobs behind your gas fireplace’s front. However, be sure to switch off the fireplace first and allow it to cool down for a while. If your fireplace has an automatic control, you only need to press a button to close the shutter. 

You may also want to adjust your fireplace damper to change the airflow further. 

A fireplace damper refers to the wood or metal place within your chimney. It lies between the firebox and the flow, regulating airflow into your fireplace together with the air vents. It also controls the heat in your living area and should remain closed when you’re not using your fireplace. 

Different types of fireplace dampers are available, and they either work manually or automatically. So, you’ll need to adjust your damper based on its type. Moreover, always let the fireplace cool down or hold the damper using an oven glove to avoid burning your hand. 

4. Adjust the Pilot Flame

If the pilot’s blue base flame starts turning yellow or orange, your fireplace might have a soot buildup. Also, you might start noticing some smoke or odor. When this happens, the fireplace isn’t safe to use, and you need to adjust the pilot flame. 

The pilot base flame may be sooty and unsteady due to gas insufficiency caused by: 

  • Gas vault obstructions 
  • Gas knob control settings 

Therefore, first, check if the gas vault is clogged and remove any debris to allow gas inflow. If the vault is okay, inspect the knob control settings. Then, make the following adjustments: 

  1. Access the gas knob controls (their location depends on the type of your gas fireplace). 
  2. Locate the “Lo-High” control button and turn it counterclockwise.
  3. If there’s no button, locate the adjustment screw. Using a screwdriver, turn the screw until a blue flame emerges. 

Note: Many gas fireplaces have manual or automatic knobs for changing the flame color. So, use the owner’s manual to locate the exact knob and adjust it accordingly. You’ll find six colors, including: 

  • Yellow 
  • Blue 
  • Red 
  • Orange 
  • Green 
  • Purple 

After selecting your preferred flame color, hold the knob for a couple of minutes to prevent it from returning to the previous position. 

5. Inspect Your Chimney or Air Vent

Adjusting your damper, air shutter, or pilot flame may not be effective if there are problems in other ventilation systems. For instance, if there are issues in your chimney or an air vent, your gas fireplace will not have good airflow. Therefore, it’s best to inspect these systems if you don’t notice any color changes on the flame. 

Although a vented gas fireplace is safer than a ventless one due to the continuous supply of oxygen from outside, it may also have some challenges. Here are possible chimney and air vent problems that you may encounter with your vented fireplace: 

  • Clogged chimney flues: The accumulation of soot, debris, or creosote obstructs a chimney flue, causing insufficient airflow. This obstruction will most likely occur if you don’t sweep the flue regularly. Hence, if you haven’t done any chimney maintenance for months, it’s best to do so to avoid problems adjusting your gas fireplace’s flame color. 
  • Inadequate installation: Many people install gas fireplaces on old chimney systems. Since they are for wood fireplaces, you should adjust the system to accommodate the gas fireplace. However, poor installation will lead to venting problems, including an inadequate draft. 
  • Acids and condensation: Another vent issue occurs when acids enter the vent system or water vapor condenses inside the flue. The problem will likely occur if the chimney flue is too big for the gas connector pipe. Therefore, the acids mix with the condensed water (vapor) to form hydrochloric acid that corrodes the duct. Consequently, the flue crumbles and blocks the chimney hindering adequate airflow into the fireplace. 
  • Broken vents: Faulty vents will impede adequate airflow into and out of the fireplace. Hence, it’s crucial to inspect the vent system regularly to identify any faults. 

6. Clean the Fireplace

When using a vent-free gas fireplace, the ventless gas logs should burn with a blue flame. Hence, any other flame color, including yellow, orange, or red, might indicate hazardous conditions. These flame colors indicate incomplete combustion and pose health complications due to soot or carbon monoxide production. 

They usually occur due to dirt or dust particles in your gas fireplace. Hence, if the gas fireplace’s flame changes from blue to orange or yellow, you should clean and adjust it. 

Here’s how to adjust the flame color in a vent-free gas fireplace by cleaning the burner: 

  1. Turn off your fireplace by following the manufacturer’s instructions. Switch the appliance off for most gas fireplaces by turning the control knob to the “OFF” position. However, if your gas fireplace is automatic, you only have to press a switch or the “OFF” button on your remote control. 
  1. Open the fireplace and locate the burner. You have to remove the fireplace screen for most units by lifting it and pulling it from the bottom. After removing the screen, you’ll most likely find the burner in the middle of your fireplace. 
  1. Inspect the burner and gas logs for dirt or dust particles. If the burner is dirty and covered in soot, clean it up using a vacuum cleaner or a brush (with fine, soft bristles). 
  1. Restore the fireplace screen. After cleaning your fireplace, put the screen back on and turn on the fireplace. The flame should now be blue. 
  1. Call a professional. If you still notice a yellow or orange pilot flame, there could be other underlying issues with your gas fireplace, including a faulty gas detector. Hence, call a professional to inspect your fireplace and diagnose the problem. 

7. Monitor Carbon Monoxide Levels

Most gas fireplaces (especially the ventless types) have monoxide detectors. These devices detect the emission of carbon monoxide when your fireplace is on. Even though gas fireplaces burn more efficiently than traditional wood fires, they can also emit carbon monoxide. 

I’ve already established that a gas fireplace can burn with a blue flame (if ventless) or a yellow flame (if vented). Hence, it’s crucial to understand what type of gas fireplace you have to know what flame color is safe. Any other color (unless you’ve adjusted it) could mean that your fireplace is emitting carbon monoxide. 

A monoxide detector will alert you if your gas fireplace produces carbon monoxide or smoke. If there is an issue, you’ll hear a chirping or a beeping sound from the detector’s alarm. Moreover, the alarm can also beep when the detector’s battery is low. 

Therefore, you should be aware of different alarm sounds to take the most appropriate action. These include: 

  • One beep every minute – indicates a low battery 
  • Four beeps and a pause signal – indicate the presence of carbon monoxide 
  • Five beeps every minute – show that the detector is faulty and needs replacement 

If you notice that your gas fireplace’s flame has started changing from blue to yellow and the alarm beeps four times, you should immediately switch off the fireplace. This sign will indicate that your fireplace is producing carbon monoxide. Be sure to alert an expert and let them inspect and fix your gas fireplace immediately. 

8. Change the Fuel

If all the other methods don’t seem to work, there’s one more alternative. If your gas fireplace’s flame isn’t appealing, you can look for another fuel for your fireplace. For instance, if you were using natural gas, you can now opt for propane. 

Moreover, if you crave the natural fire look, you can switch to wood as your fuel source. However, you can not use this option if your fireplace is ventless. Hence, you’ll require a professional to adjust the fireplace to install a ventilation system (but this is expensive). 

Final Words

Most gas fireplaces burn with a blue flame. However, some have blue base flames with yellow or orange tips. You can use various strategies to adjust the fireplace’s flame color, but always ensure that you don’t compromise the air quality in your home. Other fireplaces have color adjustments that you can change with a button. 

So, be sure to read up on your gas fireplace and learn more about what it can do. If you see anything irregular like an improperly-colored flame, you might need to have your gas fireplace inspected. 

Dan Westfield

Hi everyone! My name is Dan and I currently have two fireplaces, a wood-burning and a gas one. I cannot live without them and love to share my passion with you all!

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