If you don’t get your seasonal maintenance, you’re trusting yourself to catch when things are broken. A cracked heat exchanger can lead to a carbon monoxide leak, so this isn’t something to put off getting repaired.
There are only two signs you might notice if your heat exchanger is cracked: You don’t have heat in your home, or your carbon monoxide detector is beeping. And these are only if you’re lucky enough to have warning signs in the first place.
Before we talk about what to do if you have a crack in your heat exchanger, it’s important to understand what a heat exchanger is, how you might know if it’s cracked, and why heat exchangers crack.
What is a Heat Exchanger?
A heat exchanger is a part of your furnace that helps create warm air for your home. Gas is ignited in the heat exchanger, and the blower pushes air across the outside of the heat exchanger, warming that air before sending it into your home. If you have a crack in that vital part of your furnace, not only will your furnace not work as well as it should, but it’ll probably leak gases into your home!
How Do You Know if You Have a Crack in Your Heat Exchanger?
The scary thing is… you won’t know if your heat exchanger is cracked. Most of the time, there are no warning signs of a crack until it’s already become deadly. If you’re lucky, your furnace will stop working, but often, your furnace will keep running even with a crack and will let carbon monoxide into your home. If your furnace isn’t producing heat, if your carbon monoxide detector has gone off, or if you or your family members have headaches or flu-like symptoms, you might have a crack in your heat exchanger.
1. Your furnace isn’t producing heat.
If you have a crack in your heat exchanger, your furnace will start up like normal, but air could blow the fire out of your fire box into the burner chamber. Because of a safety sensor called the Flame Rollout Safety Detector, the fire rolling out to your burner chamber would result in your furnace shutting off. When this happens, your furnace won’t start again until you have a professional reset the sensor (and while they’re there,
2. Your carbon monoxide detector goes off.
is going off, it’s not something to ignore!
Your CO Detector May Not Go Off
Not only do detectors have a high limit before they go off, many of them never even go off at all! Your CO detector uses a silica gel and a sensor to detect the presence of carbon monoxide in the air. Over time, this gel dries up and can’t detect CO anymore. That’s why it’s important to keep track of the expiration dates of any detectors you have in your home. Typically, they dry out after about 5 or 6 years, so if your detectors are over 5 years old, we recommend replacing them.
3. You or your family members have headaches or flu-like symptoms.
Senior citizens and small children are particularly vulnerable to carbon monoxide. The same goes for your pets! Have you ever heard about how, in the past, miners would bring canaries down the mine shafts? Birds are super sensitive to CO, so the miners would know if there were dangerous levels of CO in the caves if it affected the canary.
If you have pets, small children, or senior citizens in your home, we recommend two carbon monoxide detectors instead of one.
What Causes Cracks in a Heat Exchanger?
If you don’t change your air filters often enough, they’ll get dirty. The longer you leave a dirty air filter in, the worse off your unit is gonna be! A dirty filter doesn’t allow as much air through it, and that means your unit won’t get the air it needs to help remove heat from the exchanger. If that happens, it’ll get too hot and holes and cracks can start burning through the heat exchanger!
If your ductwork isn’t the right size or it wasn’t installed properly, it can cause similar issues with airflow. Not enough airflow leads to an overheating heat exchanger.
Recommended: “5 Furnace Safety Features You Should Meet”
What Can You Do if You Have a Crack in Your Heat Exchanger?
If you have a crack in your heat exchanger, you only have two good options: replace the heat exchanger or replace the furnace. There’s no safe way to truly repair a heat exchanger.
If your furnace is 9 years old or older and it has a crack in the heat exchanger, it might be worth looking into replacing the unit rather than the heat exchanger simply because, at that age, it’s not uncommon for more parts to begin wearing down and costing you more and more in repairs. At this point, it’s just a more economic decision to replace the unit.
Should You Be Afraid of Cracks in Your Heat Exchanger?
While it may be impossible to know when your heat exchanger is cracked without the help of a professional, it’s important to know the dangers. To give yourself the peace of mind that you and your family can be safe all winter long, schedule a Check’n’Check and Check! Your safety expert will come out and inspect your unit super thoroughly for anything that could be a concern. That way, you don’t have to worry about any of this—you can let us take care of things so you can get back to the things that matter most.