A healthy functioning furnace should burn with a blue flame and a yellow tip. As a general rule around 90% of the flame should be a dark blue color, with only the top yellow or orange.  If your pilot light is more yellow than blue then there’s a problem.

In older furnaces the pilot light serves to ignite gas for the main burner; it burns constantly and steady to maintain heat to your home or business.

A pilot light requires the correct amount of gas and air to remain steady.  Too much or gas and not enough air and you may end up with a yellow or orange flame.  This basically means that the flame is starved of sufficient oxygen.  A deep blue color is the natural color of a flame that has sufficient oxygen to keep it burning.

What’s the cause of a yellow flame?

The most common cause is a clogged air intake valve which leads into the pilot light.  A yellow flame can also be caused by damage and a faulty installation.

When the flame is yellow, it means that there is incomplete combustion of the gas which can lead to harmful carbon monoxide being released.  The flame may go out completely due to insufficient conditions to stay ignited.

The symptoms of carbon monoxide poisoning

Carbon monoxide is an invisible, odorless gas, which makes it particularly dangerous.  The main symptoms of exposure include headaches, breathlessness, dizziness, nausea and even collapse.

If you think you have carbon monoxide poisoning call a doctor right away.

What to do about a yellow flame?

If the yellow flame is persistent,  or the pilot light keeps going out turn off the gas supply and call a heating professional.

 

Is it time to replace your furnace?

Furnaces with standing pilot lights were common up until the mid 90s when electric ignition started to replace them.  If you still have one of the old style furnaces it is likely to be nearing the end of its lifespan (typically 15-20 years).

If you would like help switching to a newer, more energy efficient model call Superior Comfort for a reliable replacement and installation in Ansonia, Shelton, Seymour, Woodbridge and the surrounding area.