Everything you need to know about a broken heat exchanger

Should you consider repairing your heat exchanger? Do you really need to replace your furnace? Find out what you need to know about your heat exchanger so you can avoid costly repair scams.
When your furnace is on the fritz, the last thing you want to hear from the service man is “cracked heat exchanger.” Why? It almost always means it’s time for a new furnace. However, there may be hope still.

Not necessarily. This is where you have to be careful. Less than honest repairmen will try to make you think the small crack is the Grand Canyon. In other words, they want to sell you a new furnace. You might need one but get a second opinion first.

According to the Air-Conditioning, Heating & Refrigeration Institute (AHRI), the crack will be easily visible to the naked eye. Be wary of the technician who tries to show you a picture of the crack. Instead, ask to see the heat exchanger when they replace the furnace. Even if you don’t know the difference between an igniter and blower motor, you should be able to see the obvious crack in the heat exchanger.

There really isn’t much of a debate on this. Due to the cost of repairing the heat exchanger, it makes more sense to replace the unit. In fact, it might be a couple of hundred dollars cheaper. You should also consider that most heat exchanger cracks occur when a furnace is around 10-years-old or more. Rarely do cracks occur under five years. If you do have a failure on a relatively new system – check your warranty – you may be covered.

Replacing a furnace is a major inconvenience to your family and your pocketbook. However, think of the alternative. The heat exchanger not only helps deliver heat to your home, it also contains the combustion process. When it cracks, combustion by-products like carbon monoxide can get into your home, which can be dangerous. That brings us to another point – it’s always a good idea to have a carbon monoxide detector in your home.

Hopefully your furnace problem is not the heat exchanger. If you think you're being scammed, get a second opinion. If you don’t already have a trusted repair man, ask your friends or family for a referral.