A cracked heat exchanger can affect your furnace’s performance and pose serious safety risks, including potential carbon monoxide exposure. Common warning signs include soot buildup, unusual odours, frequent shutdowns and poor heating. Restricted airflow, overheating and normal wear can all contribute to cracks.
A professional inspection can confirm the damage and determine whether the heat exchanger or entire furnace needs replacement. AAA Heating and Plumbing provides 24/7 emergency furnace repair in Calgary, including temporary heaters for customers while their furnace is out of service.
What does a furnace heat exchanger do?
Your gas furnace burns fuel to produce heat. The furnace heat exchanger transfers that heat to the air moving through your home. Its metal walls keep combustion gases separate from the indoor air that passes through your ducts.
A crack in the heat exchanger can weaken that barrier. This creates a potential safety risk, even if the furnace still seems to be heating your home. A running furnace does not prove that its heat exchanger is safe.
What causes a heat exchanger to crack?
The metal heats up and cools down each time your furnace runs. Over time, that repeated movement can cause wear. Excess heat can also place stress on the metal.
A dirty filter or restricted airflow may cause overheating. These conditions can contribute to damage, but a technician needs to assess the cause. Replacing a clogged filter will not fix an existing crack. Regular maintenance can help identify operating problems before they cause further damage.
Warning signs that need an inspection
Possible signs of a cracked heat exchanger can overlap with other furnace problems. Look out for these changes:
- Soot buildup around the furnace.
- Unusual odours during operation.
- A furnace that turns on and off repeatedly.
- Poor heating or an unexplained change in performance.
- Visible damage identified during a professional inspection.
These warning signs do not confirm a crack. Common furnace problems, including ignition faults and airflow restrictions, can cause similar symptoms. Do not remove furnace parts or try to inspect the burners yourself. Tell your technician what changed and when you first noticed it.
AAA Heating and Plumbing offers video inspections of furnaces. Ask our team about a video inspection when booking service for a suspected heat exchanger problem.
What if your carbon monoxide alarm sounds?
Carbon monoxide has no smell, colour or taste. You cannot rely on an odour to detect it. If your alarm sounds, leave the home immediately and move to fresh air. Once outside, call 911 or your local emergency services.
Do not stay inside to find the source, turn off equipment or gather belongings. Return only when emergency responders say it is safe. Have the problem corrected by a professional before using the affected equipment again. A furnace repair appointment does not replace an emergency response to a carbon monoxide alarm.
When should you call for emergency furnace repair?
Call for emergency furnace repair if your furnace stops working during cold weather or a technician identifies a condition that makes it unsafe to use. If you suspect a cracked heat exchanger, stop using the furnace and arrange a professional inspection.
When you call AAA Heating and Plumbing, explain whether you have no heat, repeated shutdowns or a suspected safety issue. Share the furnace make and model if you have that information readily available. This helps us understand the service request before the visit. Do not restart a furnace that has been shut down for safety.
Free heaters while you wait for repair
AAA Heating and Plumbing offers heaters to all customers in the case of an emergency furnace repair. Tell our team that your furnace is out of service when you call, and we can discuss the temporary heating arrangements.
Temporary heaters provide heat while the furnace issue is addressed. If your home has been evacuated because of carbon monoxide, wait for clearance before returning or using heaters inside
Should you replace the heat exchanger or the furnace?
A confirmed cracked heat exchanger generally calls for replacement of the damaged component or the furnace. The choice depends on the furnace’s age, overall condition, warranty and the work required.
Ask for a clear explanation of the damage and a written estimate. Compare the full cost of each option, including labour and any parts that the warranty does not cover.
Before approving the work, ask these questions:
- What evidence shows that the heat exchanger has failed?
- Is the replacement part available for this model?
- What does the warranty cover, and what will I pay?
- How long is the furnace expected to remain out of service?
Book furnace service in Calgary
Keep up with filter changes and professional inspections according to the manufacturer’s instructions. Report new noises, shutdowns or heating issues instead of waiting for a complete loss of heat.
AAA Heating and Plumbing has served Calgary for 20 years. We handle furnace installation and replacement for both residential homes and businesses. For an emergency furnace repair, call 403-474-5443. We offer 24/7 emergency service and heaters to all emergency furnace repair customers.