3 Signs Of A Cracked Furnace Heat Exchanger

The heat exchanger is the chamber inside of a gas furnace where combustion takes place. Under normal circumstances, the heat exchanger transfers heat from burning fuel into the air around it, and then expels waste gas through the furnace flue.

Overheating, corrosion, and advanced age can all cause a furnace heat exchanger to crack. A furnace with a cracked heat exchanger is unsafe to operate because it may leak toxic gasses into your home's breathable air. These are the three signs of a cracked furnace heat exchanger that every homeowner should be aware of.

1. Yellow or Flickering Burner Flames 

When your furnace is receiving the right mix of fuel and air, the burners should emit steady blue flames. A cracked heat exchanger can disrupt the mix of air and gas during combustion, which can lead to noticeable disruptions in the burner flames.

You may have a cracked heat exchanger if the burner flames appear to flicker or are yellow or orange in color. In most furnaces, you can observe the burner flames safely by removing the furnace compartment cover and turning on your furnace. If you notice an unusual chemical smell during this step, turn your furnace off and call an HVAC professional for further investigation.

2. Strange Noises While Your Furnace is On

A defect in a critical component like the heat exchanger can cause your furnace to exhibit strange noises while it's running. A metallic rattling noise is one sound to listen for that could point to a cracked heat exchanger. This noise occurs when pieces of the cracked heat exchanger vibrate separately and knock against each other.

You may also hear banging or popping noises inside your furnace when the heat exchanger is cracked. These sounds can be caused by the expansion and contraction of the weakened pieces of metal in your heat exchanger. 

3. Soot Around Your Furnace or Vents

Soot is carbon residue that can collect on surfaces as a result of incomplete combustion. A cracked heat exchanger can cause soot buildup by disrupting the mix of air and natural gas inside your furnace's combustion chamber.

If a cracked heat exchanger is causing your furnace to produce excessive soot, you may see it both inside and around your furnace assembly. In some cases, soot can be blown through your ductwork and may be visible around your vent registers.

The issues mentioned above can all be caused by a cracked heat exchanger, one of the most critical furnace problems. Schedule a professional furnace inspection if you notice any of these symptoms in your home.

For more information, contact heating repair services