Heating, Air Conditioning, Fridge, HVAC/Furnace Flame


I was checking my furnace and the pilot light flame stays blue, but I noticed the flames from the furnace are orange. Is this normal or should the flames be blue too? Also, I've checked the fan, motor, and vents and cannot find out what the loud knocking sound is that is waking me every morning when the furnace first turns on for the day. It is loud and comes from my bedroom vent, about 10 bangs in a row. This sound only happens when it is first turning on. What could this be?

ANSWER: Kayla,
I would have to listen to the knocking sound to get a clue what it is?
Your burner flame should be a soft blue.

---------- FOLLOW-UP ----------

QUESTION: Is it dangerous if the flame is orange instead? Also, after the heat shuts off there is always this pitter-patter sound coming from my bedroom vent. It's annoying, but I've heard it's from the metal heating and cooling. All my duct work is under the house, so is there anything I can do from my vent to get rid of this sound?

All furnace, duct work, etc. installations are not the same,they can be as different as night and day, When something gets heated it expands, when it cools it contracts, metal and wood do a lot of expanding and contracting, when the blower comes on it can pressurize the duct work, when it turns off it can move back in, electric controls can buzz and vibrate, the list goes on and on, you need to have a qualified person listen and correct the problems or live with it?
If your furnace burners have air adjustments you can adjust the flame color, to much red can be a fume problem, to much yellow can be an air problem, a soft blue flame is what it should be.
Depending on the cause would determine if it,S dangerous?
Call your gas utility company and see if they will do a no charge inspection of the burner flame.

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Jim Barnhart


Fifty + years conditioning the air.


Answer questions about , residential and commercial. Answer questions about sheet metal fabrication. Fifty years plus experience. No answers for oil equipment, No answers for kitchen appliances, No answers for laundry appliances, I don't specialize in one particular area of the HVAC area, I'm more of a General Practitioner, Limited in refrigeration/

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