Heat Exchanger Repair in Herndon, VA
The heat exchanger is where your furnace's flame heats your home's air, and the wall between combustion gases and your family. When it cracks, it needs immediate attention. We inspect, diagnose, and make it safe.
Warning Signs Your Heat Exchanger May Be Cracked
A cracked heat exchanger is not a wait-and-see problem. If any of these sound familiar, shut the furnace down and call.
- ✓Soot around the furnace
Black soot on or around the cabinet points to combustion problems inside.
- ✓A strange, sharp smell when heat runs
Cracked exchangers can push exhaust odors into your supply air.
- ✓The flame looks wrong
A healthy burner flame is steady and blue. A flame that dances or changes color when the blower starts suggests a breach.
- ✓CO detector going off
A cracked exchanger is a leading source of furnace CO. If the alarm sounds, get out and call for help first.
- ✓Visible cracks or rust
On inspection, we look for cracks, rust-through, and separated seams in the exchanger metal.
- ✓The furnace is aging
Metal expands and contracts every cycle. After many heating seasons, fatigue cracks become more likely.
What a Heat Exchanger Repair Involves
We move carefully here, because the stakes are your household's air.
Shut down and inspect
We shut the furnace down and inspect the exchanger with mirrors, cameras, and combustion testing.
Show you the damage
If we find a crack, you see it. Photos, not just our word.
Make it safe
A cracked exchanger means the furnace stays off until it is fixed. We lock it out so it cannot fire accidentally.
Repair or replace the part
Some exchangers can be repaired. Many need the part replaced. We explain your options honestly, including when a new furnace makes more sense.
Heat Exchanger Questions
What homeowners ask when this part comes up.
What does a heat exchanger do?
It separates the flame's hot combustion gases from the air your furnace blows through your ducts. You get the heat. The exhaust goes up the flue. A crack breaks that separation.
Can a cracked heat exchanger be repaired?
Sometimes, depending on the crack's location and the exchanger's condition. Often the part needs replacing. On older furnaces, replacing the whole unit can make more sense. We lay out both honestly.
Is a cracked heat exchanger dangerous?
Yes. It is the main way carbon monoxide gets from a furnace into a home's air. If you suspect one, turn the furnace off and call us before running it again.
How do you find a crack?
Visual inspection with mirrors and cameras, plus combustion analysis that shows exhaust gases where they should not be. Small cracks hide. We use more than one method.
Why do heat exchangers crack?
Every heating cycle expands and contracts the metal. Over many seasons that cycling fatigues the steel, especially with oversized furnaces that short cycle, restricted airflow, or neglected maintenance.
How long does a heat exchanger repair take?
Part replacement is usually a full-day job once the part is in hand. Some older models have long lead times on parts. We tell you upfront what to expect.
Last updated: October 19, 2026
This part protects your family. Treat it that way.
If you suspect a cracked heat exchanger, don't run the furnace. Call now and we will inspect it properly.