
How to Fix a Cracked Furnace Heat Exchanger
- Check the Furnace Heat Exchanger. Before you can do any repairs, you should make sure that you check over your furnace heat exchanger thoroughly.
- Make the Repair. Once you are ready to begin the repair itself, put on your safety glasses and gloves. ...
- Aftercare. Now that you have fixed the heat exchanger, replace it in the furnace. ...
How do you repair a furnace heat exchanger?
The basic steps of repairing your furnace heat exchanger include removing the metal clips and testing the furnace. When you remove the metal clips from the heat exchanger, you will need to take some metal shavings with an X-Acto knife and smooth out the sharp ends on both sides of the clip.
What should I do if my heat exchanger is not working properly?
Make sure to then call a professional repair technician to help you with the difficult repairs. Tackling your heat exchanger’s issues on your own can lead to further damage to the equipment and will require more downtime to resolve the problem on your own.
What is a furnace heat exchanger?
Furnace heat exchangers are a critical component of furnaces. When you get your furnace, there is a furnace heat exchanger (also called furnace filter or furnace blower) which needs to be installed in the furnace. The furnace heat exchanger carries both heat and air from the furnace.
Why is regular maintenance necessary for your heat exchangers?
This is why regular maintenance is necessary not only for your heat exchangers but also for the machinery that it is connected to. You will want to avoid having to repair this equipment as much as possible, but if you start noticing poor performance or damage to your equipment, it is best to call professionals to help you with repairs.

How much should it cost to replace a heat exchanger?
between $1,000 and $2,000Replacing a heat exchanger typically costs between $1,000 and $2,000 or $1,500 on average.
Is it worth replacing a heat exchanger?
If your heat exchanger is cracked, your furnace is probably nearing the end of its life (18-20 years). If that's the case, then it's usually not worth the money to replace the heat exchanger. No matter who you ask, replacing a heat exchanger will be expensive.
How do I fix a leaking heat exchanger?
It is impossible to repair a cracked heat exchanger. The only solution is replacing the heat exchanger (which is very expensive) or replacing the entire furnace.
Can heat exchangers be welded?
NO! Cracked heat exchangers should not be welded or repaired. Repairing a cracked heat exchanger requires welding both sides of the crack to ensure stopping all leaks. In most residential and small commercial heating units, this is not possible.
Can a heat exchanger be repaired?
Unfortunately, heat exchangers cannot be repaired. When a heat exchanger cracks or rusts through it must be replaced. Because the heat exchanger is at the center of the furnace, nearly the whole furnace must be disassembled. Even if the parts are covered under warranty, the labor and freight will start around $500.
Can I run my furnace with a cracked heat exchanger?
Rule #1: If your Heat Exchanger has been deemed cracked by a HVAC professional you should NOT be running it. Unfortunately, some owners will attempt to run their furnace even when a cracked heat exchanger has been detected.
What are the signs of a cracked heat exchanger?
Six Signs Your Furnace Heat Exchanger May be CrackedStrange smells. A malfunctioning heat exchanger will often create an unpleasant and strong odor that smells similar to formaldehyde.Soot Build-up. ... Corrosion & Cracks. ... Change in the flame appearance. ... Audible Sounds. ... Presence of Carbon Monoxide.
How long does a heat exchanger last?
15 to 25 yearsIn the past, heat exchangers were often built with heavy metals, such as cast iron. These exchangers can last as long as 30 or 40 years, much longer than the steel exchangers most manufacturers build today. Modern stainless or aluminized steel heat exchangers typically have a life span of 15 to 25 years.
How do I test a heat exchanger?
0:152:21Simple Furnace Heat Exchanger Test | Lennox Learning SolutionsYouTubeStart of suggested clipEnd of suggested clipAnd easiest ways to test them while it's true we can disassemble the heat exchanger take theMoreAnd easiest ways to test them while it's true we can disassemble the heat exchanger take the manifold. The burners out and do a visual inspection.
How long should a heat exchanger last?
about 15 yearsThe heat exchanger is responsible for heating the air that circulates through your home in the winter. Heat exchangers usually last about 15 years. If you invest in maintenance, yours might even last 20.
How do you tell if your furnace has a cracked heat exchanger?
Six Signs Your Furnace Heat Exchanger May be CrackedStrange smells. A malfunctioning heat exchanger will often create an unpleasant and strong odor that smells similar to formaldehyde.Soot Build-up. ... Corrosion & Cracks. ... Change in the flame appearance. ... Audible Sounds. ... Presence of Carbon Monoxide.
What happens if your heat exchanger is cracked?
What if Your Have Cracked Heat Exchanger? When you're told that your heat exchanger is cracked, exhaust gases can leak into the air instead of entirely into the flue pipe. The most hazardous of these gases is Carbon Monoxide. For this reason it is a must for you to have a carbon monoxide detector in your home.
How often do heat exchangers crack?
If you've poorly maintained your system, rust can build on the components and develop cracks. The average lifespan of a furnace's heat exchanger is 15 years. If your gas furnace is about that age, the chances are high that the heat exchanger can crack.
What is a Heat Exchanger?
First of all, let’s take a look at what a heat exchanger actually is to help you identify where the problem lies.
How to Diagnose a Faulty Heat Exchanger
As with any other internal component of a boiler, the heat exchanger can become faulty over time through wear and tear, leading to a number of issues which negatively impact the effectiveness of your central heating system.
Common Heat Exchanger Problems
One problem commonly associated with the heat exchanger is a buildup of limescale. In parts of the country with hard water, limescale can wreak havoc on appliances and pipework as the high levels of calcium and magnesium minerals build up, leaving a chalky white deposit and causing cracks and other types of damage to the system.
Common Symptoms of Limescale Buildup
Limescale deposits can cause overheating within the system, leading to steam and bubbling which can produce whistling noises called kettling.
Common Symptoms of a Damaged Heat Exchanger
When your boiler is turned on, the burner flame should be steady and blue in colour. If you find that the flame is moving or flickering a lot and yellow in colour, this can indicate either a dirty burner or a crack in your heat exchanger.
How Much Does it Cost to Replace a Heat Exchanger Vs Replacing Your Boiler?
The cost of a new heat exchanger typically lies between £400-£600- a hefty bill to pay if your existing boiler is old and the warranty on parts has expired.
