A cracked heat exchanger is one of the more serious furnace problems you'll face. It's serious because it could pose a health threat to your family and because the repairs can be expensive. Here's a look at what causes a heat exchanger to crack and what a furnace repair professional might recommend to fix the problem.
The Purpose Of The Heat Exchanger
The heat exchanger is the main working part of the furnace that creates heat. Combustion gas from your furnace collects in the heat exchanger and makes the metal hot. When air blows over the hot metal, it picks up heat and distributes it through your house. The combustion gases, such as carbon monoxide, then release through the flue.
The Reasons A Heat Exchanger Can Crack
One reason the metal can crack is due to low airflow that allows the metal to get too hot. The cause of low airflow could be due to a clogged filter you forgot to change. The problem might also happen due to a lack of annual maintenance, the wrong size ducts, or rust.
If you have a high-efficiency furnace, it probably creates condensation. Condensation is created and then dries out when the metal gets hot. If something malfunctions and the condensation doesn't drain or evaporate, the metal can rust and get tiny holes or crack.
The Furnace Repairs For A Bad Heat Exchanger
Your furnace repair professional has to check the furnace thoroughly to verify the furnace has a cracked heat exchanger. This might be done visually and by checking for carbon monoxide levels in your home. If the exchanger is cracked, repairs must be done before you can turn your furnace back on.
A cracked or rusted heat exchanger usually can't be repaired safely. Instead, the exchanger has to be replaced. If your furnace still has several years of service left, and the heat exchanger is under warranty, the repair person may recommend replacing the exchanger.
If your furnace is near the end of its life, your repair person might talk about replacing the entire furnace instead. You may be provided with quotes for both options so you can compare prices and decide what is right for you.
Replacing a heat exchanger is an expensive furnace repair even if the part is under warranty because the furnace repair professional has to take your furnace apart, and the repairs can be time-consuming and difficult. You can sometimes avoid the need for this repair by having regular maintenance done on your furnace and by ensuring your furnace always has adequate airflow.