Worried your natural gas or propane furnace has a cracked heat exchanger? You might be right if your heating system isn't heating, or you notice any of the other cracked heat exchanger symptoms described below.
Here is a TL;DR of the signs and risks of a cracked heat exchanger.
- Safety Hazards: Leaks dangerous carbon monoxide, causing CO alarms to sound or flu-like physical symptoms.
- System Indicators: Watch for a yellow burner flame, soot buildup, or the furnace repeatedly shutting itself off.
- Primary Causes: Overheating due to clogged filters, dust accumulation, corrosion, or units older than 15 years.
- The Outcome: A cracked heat exchanger cannot be repaired; the entire furnace must be replaced for safety.
Having problems with your furnace? Call Reliable Heating & Air at (770) 594-9969 or schedule an appointment.
Our licensed, NATE certified, and EPA certified furnace techs will inspect your system to diagnose the issue. They'll let you know whether the problem is a cracked heat exchanger and if you need a furnace replacement. They'll also give you the same five-star customer service Atlanta residents have been getting for the past 40 years.
What is a Heat Exchanger?
The heat exchanger is the part of your furnace that burns off gas to generate heat. Modern heat exchangers are typically constructed from aluminized steel or stainless steel for durability. After the heat is generated in the heat exchanger, the blower motor kicks on to pull in cold air from your home, circulate it over the heat exchanger's chamber, and carry the heated air throughout your home via ductwork.
A crack in the heat exchanger, unfortunately, means bad news for your furnace.
5 Signs of a Cracked Heat Exchanger
Cracked heat exchanger symptoms:
Your furnace isn't heating. Furnaces today have a number of safety features to help protect you and your family from potentially harmful issues. One of these features includes a flame rollout sensor that detects when the flame burning off the gas rolls outside the chamber it's supposed to stay inside of - which is what can happen when there's a crack in the heat exchanger. When this sensor goes off, it tells the furnace there's something wrong at this step of the startup process and shuts off your system. This is actually the best case scenario if you have a cracked heat exchanger! Many times, Atlanta homeowners don't know they have a faulty or defective heat exchanger until they notice more damaging signs or start experiencing health issues due to carbon monoxide poisoning.
Weak yellow furnace flame. The furnace burner flames should be strong flames that are primarily blue with a hint of yellow. If the furnace flames are yellow all over, that means the flame isn't strong enough to heat your home - indicating a cracked heat exchanger or another problem with the furnace. This can also indicate issues with the pilot light or ignition system that require immediate attention from a qualified technician.
Soot on the heat exchanger chamber. A crack in the chamber means the gas isn't combusting properly. This causes more carbon in the system, which in turn produces more soot. Excessive soot buildup can also contaminate your indoor air quality and spread throughout your ventilation system.
Your carbon monoxide (CO) detector is going off. A cracked heat exchanger can cause incomplete combustion inside your furnace, which produces carbon monoxide: a colorless, odorless and toxic gas that can cause serious health issues and even death in people (especially when sleeping). So if your CO detectors keep going off and you can't figure out why, a broken or leaking heat exchanger may be the culprit. If you have a gas furnace but no CO detectors, consider installing some in bedrooms and other areas where people sleep. This is a critical and urgent safety issue that requires emergency service.
You notice symptoms of carbon monoxide poisoning. Since a cracked heat exchanger can emit CO, people in your household are at risk of CO poisoning. Signs of CO poisoning can include headaches, nausea, dizziness, fatigue and other symptoms that might be confused with the flu. You can learn more about the dangers and causes of carbon monoxide in our blog.
Since a damaged heat exchanger risks CO poisoning, you can't repair or replace the heat exchanger. You'll need to replace your entire system. If you notice signs of a bad heat exchanger or are worried whether your furnace is safe to operate, call a professional to inspect your system.
What Causes a Cracked Heat Exchanger
A faulty heat exchanger can result from various causes:
Overheating. Heat exchangers can crack if there's too much heat building up inside your system. This is one of many reasons it's important to replace filters regularly and maintain consistent airflow in your system. Preventive maintenance through regular filter replacement and tune-ups can help prevent overheating and extend your furnace's lifespan.
Dust buildup. Dust accumulating in your system can clog filters, block blowers and insulate coils. This restricts airflow, which causes your system to overheat and the heat exchanger to crack. Poor ventilation and inadequate air quality management can accelerate this deterioration.
Corrosion. A poorly maintained furnace can rust or corrode, which will eat away at the heat exchanger chamber and eventually weaken it so much that it cracks. Issues with the condensate drain, flue, or exhaust system can introduce moisture that accelerates corrosion in the heat exchanger.
Old age. Furnaces only last about 15 years. The constant heating and cooling of the system will weaken the metal heat exchanger over time and cause it to crack. Aged heating systems become increasingly inefficient and prone to malfunction, making replacement a better long-term investment than continued repairs.
Think you have a cracked heat exchanger? Call us at Reliable Heating & Air.
Call us today at (770) 594-9969 or schedule an appointment for a free in-home estimate.
We offer the most reliable furnace replacements in the Atlanta area. As a family-owned, locally owned, and trusted HVAC contractor established in the Atlanta region, we're a manufacturer-authorized and factory-trained Trane certified dealer and Goodman dealer. Our uniformed, background checked, and drug tested furnace techs will thoroughly inspect your system to make sure a broken heat exchanger is the problem before giving you recommendations for a new system. We provide upfront pricing with no hidden fees, and all our work is warranty backed, including parts and labor coverage. Our professional staff offers same-day service and 24/7 availability for emergency furnace repair needs.