Why are the flames in my fire pit invisible or blue when I first light it? - Gas Fire Pit and Fireplace Blog

Hearth Products Controls Co.

This is a new venture for HPC. We were looking for another avenue to get information out to our dealers and distributors. Whether it is technical, catalog updates or some information you may just find useful.

Why are the flames in my fire pit invisible or blue when I first light it?

We often receive calls from homeowners asking "Why are the flames so hard to see or blue when we first light our fire pit?"

There are a couple of factors that cause your flames to look like this for a short period upon start-up.

One is that blue flames indicate complete combustion of the gas. There is a high oxygen ratio mix. The amount of oxygen is controlled by an air mixer on your fire pit. When you first start up your fire pit, there is a lot of air (oxygen) in the gas lines. The fire will burn a blue color until all the air is purged from the gas lines. Blue flames burn almost twice as hot as yellow flames.

The second is the media used in your fire pit. As the flames go through the media and reflect off of logs and embers, soot and other small particles mix with the flame, affecting how the oxygen mixes with the burned gas. As the embers and logs heat up, they take on a glow. The flame height will also differ depending on what type of media you use. 

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