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Cracked Heat Exchanger: Do I Need a New Furnace?

natural-gas-burnerWe’ve written before about the importance of having your furnace’s heat exchanger regularly checked by a professional. This is a part of our routine preventive maintenance program, the Ultimate Service Agreement, and it’s a vital inspection to make sure that a furnace operates as safely as possible. What our technicians look for when they examine a heat exchanger is signs of cracks along it or corrosion that can lead to those cracks. A cracked heat exchanger can allow toxic combustion gases to escape into the airflow moving into the rooms around a house—a dangerous situation!

Furnace owners often feel nervous when they learn their furnace may pose a safety risk. This leads to the question whether they should have the furnace repaired—which means replacing the heat exchanger—or instead have a new gas furnace installed.

A cracked heat exchanger usually means an over-the-hill furnace

The damage to a furnace’s heat exchanger that can lead to cracks usually occurs because the heating system is near the end of its service life, probably older than 15 years and maybe 20. Corrosion is the most common of the aging effects that can trigger cracks in a heat exchanger. The reaction of combustion gases with the metal in the heat exchanger leads to corrosion over time (faster if there is poor ventilation).

We don’t recommend keeping a gas furnace that’s more than 20 years old, since it can mean numerous problems along with the safety risk. If a technician discovers a cracked heat exchanger in a furnace that’s older than 15 years, it’s much more cost-effective to have the furnace replaced rather than just the heat exchanger. A furnace this old doesn’t have many more years of quality service left to it, and you’ll need to replace it soon anyway. If you install a higher efficiency furnace, it will start paying back the replacement cost with better energy performance.

Replacing the heat exchanger

The cost of putting in a new heat exchanger varies depending on the furnace. If you have a younger furnace that might have another decade of service in it, you’ll have to weigh the cost of the heat exchanger replacement against getting a new gas furnace. In general, if the heat exchanger replacement is more than half the cost of a replacement furnace, the new furnace is a better option. Let your HVAC technicians help you make the best choice. If the cracked heat exchanger is a sign of larger problems with a newer furnace (unfortunately a common situation if amateurs installed it), then a replacement is both the more effective solution and the safer one.

No matter if it’s time for a heater replacement or a targeted heater repair in Fresno, CA, we’re the experienced HVAC contractor to call in the Central Valley. Remember, ­only licensed professionals should work on a natural gas furnace. We’ll not only ensure you have the best furnace for your winter heat, but that you and your family will be safe. When it comes to gas furnaces, safety is always our top priority!

Purl’s Sheet Metal & Air Conditioning: Quality Is the Cornerstone of Our Success Since 1952.

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