If your home has a gas furnace, you may worry about the unit giving off carbon monoxide. Because the gas does not have any odor and cannot be seen, you may have been planning to get a carbon monoxide alarm but are wondering if there are any tell-tale signs of its presence. If so, look for the following signs that your gas furnace is most likely giving off carbon monoxide and should be looked at and repaired immediately by a professional.

1.  Pilot Light's Normally Blue Color Has Changed to Yellow

One sign that your home's gas furnace may be burning off carbon monoxide is when the pilot light changes color. Normally, when enough oxygen is mixing with the natural gas, the light will have a cool blue color.

However, if the flame is not getting enough oxygen, it will start to turn yellow. You may see yellow mixed in with blue. Or, if the oxygen level is very low, the flame will be almost completely yellow.

Because there is not enough oxygen, not enough of the gas will burn off cleanly. When this happens, the byproduct is carbon monoxide. This issue could be caused by a clogged or damaged thermocouple, which would need to be replaced by a professional.

2.  Black Carbon Coats the Surfaces Around the Pilot Light and Burner

Another sign that your gas furnace is not burning enough gas off and is emitting carbon monoxide is when you start seeing a black coating the surfaces around the pilot light and burner. You may also see black smoke rising from the flames themselves.

When too much fuel is being released into the air, the carbon produced will settle on any surfaces surrounding the fire. If you do see black carbon, there could be an issue with the thermocouple, or the burners may be partially clogged or damaged. In either case, you will need to have the affected part replaced.

3.  Members of Your Household Start Showing Symptoms of Carbon Monoxide Poisoning

Along with physical signs inside of your gas furnace, you and/or your family members may start to feel ill if there is a lot of carbon monoxide being released into the air. This is especially true if any of the members of your household have existing respiratory problems, such as asthma or chronic obstructive pulmonary disease (COPD).

Since carbon monoxide is not detectable without a detector, you and your family members may be exposed to the invisible gas long enough to start showing symptoms of carbon monoxide poisoning. If anyone in your household starts to feel constantly dizzy, have unexplainable headaches, or even start suffering from shortness of breath, start looking for the other signs discussed above.

Also, get a detector if you do not already have one. If the alarm goes off, make sure that there is ventilation in your house by opening up the windows. Along with contacting your family's doctor about the symptoms, you need to turn off the furnace until you have it looked at by a professional to determine what is causing the emission of the gas.

If you notice the above signs and purchase a carbon monoxide detector that sounds an alarm as soon as you turn it on, you need to have your gas furnace inspected by a professional immediately. Contact an HVAC contractor that offers furnace repair services to let them know that you believe that your heater is giving off carbon monoxide. They can then send someone out as soon as possible to find the cause of the gas production so that they can take action to fix the issue.

To learn more, contact a furnace repair contractor.