What Different Furnace Flame Colors Mean

Here’s an energy-saving tip: the color of your furnace flame can give you an idea of your heating system’s fuel efficiency. Blue flames with a light blue triangle at their center are a sign your furnace is in good condition and is burning fuel efficiently. 

But what if the furnace flame is yellow or orange? What do these flame colors mean? In general, they’re a sign that fuel combustion in your furnace is inefficient and that your heating system should be inspected by a professional HVAC technician. 

A-1 Comfort Care, your trusted HVAC and plumbing service contractor, elaborates further on what these flame colors mean below:

• Blue – Complete or efficient combustion creates blue flames, which are hotter than other flame colors.
• Yellow – In addition to being a sign of inefficient combustion, yellow flames indicate the production of carbon monoxide, an odorless, colorless, tasteless gas that can cause headaches, nausea, hallucinations, and in severe cases, blackouts. (Most patients have described the symptoms of carbon monoxide poisoning as flu-like.) This flame color is produced when condensates are burned along with methane.
• Orange – Yellow and orange flames generate the least warmth.

Other Signs of Incomplete or Inefficient Combustion

In addition to yellow and orange flames, you should keep an eye out for flames that are flickering, soot on the furnace filter (located in the blower compartment) and excessive vapors on the interior walls and windows. If you notice any of the aforementioned signs, you should have a professional contractor from a heating and plumbing services company inspect your furnace. 

How to Tell When It’s Time for a Furnace Upgrade

Yellow and orange flames are a sign of inefficient combustion, which could, in turn, indicate that your furnace is nearing the end of its lifespan. Gas furnaces have an average lifespan of 10 to 15 years. If your furnace’s age is within this range, you might need to replace it soon. If you’re not sure about the condition of your furnace, it’s best to consult a professional heating contractor. 

A-1 Comfort Care has been providing local plumbing services as well as HVAC services since 1999. To request free estimate, call us at (732) 578-0379 or fill out this form. We serve homeowners in Wall and Freehold, New Jersey, as well as surrounding NJ communities.