Furnace flame color?
 

Hi we have a bit older furnace (79 lennox) and I was wondering about the color of the flame? Ive cleaned out the heat exchange, burners, and generally the inside. I know the flame should be a blue tint, but its mainly a mix of yellow and blue. Is there something I may have overlooked? Thanks, Josh

From Cozyparts.com ( http://cozyparts.com/lennox-parts/fo...p?TOPIC_ID=819 ).

At the first indication of incomplete combustion (yellow flame instead of blue, or soot present), call for service immediately. Improper combustion can cause carbon monoxide buildup which is potentially fatal!

I know for a fact the burners are clean (I took them out and thoroughly cleaned them. With our older model (Lennox G11E) it has an air adjustment shutter attached to the burners.. I was kind of suspecting this.

Might be?? Blue flame ideal. Yellow generally means incomplete combustion Generally if nobody has messed with he setting (like your air shutter adjustment) indicates a dirty burner assembly or passages or somthing else that has changed. However ether way yellow not that good. I bit older as of 79 means your furnace is 29 years old. How were the burners cleaned?? could there be partial blockages from inside rust that may have been missed?

I cleaned the burners with a bottle brush and used a tool made from sheet metal to clean out the actual flame ports. Then to double check, held the burners face up to a light until I could see light through all the ports inside. I cleaned out the heat exchange as best as I could. I had seen through the Lennox manual that you should drop a chain attached to something down the heat exchange to work back and forth anything building up. But never got a chance to try it.