Your furnace might stop working if you're lucky, but most often, it will keep running even with a crack, allowing carbon monoxide to seep into your house. The only signs that you have a damaged heat exchanger are no heat during the winter, reoccurring flu-like symptoms, or a beeping carbon monoxide detector.
Visible Cracks or Holes
A clogged air filter can even cause heat exchanger cracks due to overheating the system. Corrosion is another factor, especially in older gas furnace systems or those exposed to moisture. The corrosive effects gradually eat away at the metal, compromising its integrity.
Quick and dirty heat exchanger test is to shut off the heat and turn on the blower. Stick a grille lighter in each burner cell and watch for flame movement. If the lighter flame moves or blows out, you have a bad cell and thus a bad heat exchanger.
If you notice strange smells, like formaldehyde or any other strong chemical smell, it strongly indicates that your heat exchanger is cracked. It also means dangerous gasses, like carbon monoxide, are leaking into your home. You should immediately evacuate and call 911.
Although a furnace will continue to heat your home even with a cracked heat exchanger, it is not safe to continue using your furnace. Using a cracked heat exchanger allows for certain toxic gases to escape from the furnace including carbon monoxide, nitrous oxide, and sulfur dioxide.
A heat exchanger can be repaired in some instances, but this is often considered a temporary solution rather than a permanent fix. Repairing a heat exchanger involves welding the cracks or applying heat-resistant epoxy.
Unfortunately, the cost of replacing a heat exchanger isn't the most affordable choice. The cost of replacing a heat exchanger ranges from $2,000 to $3,500. Replacing your furnace's heat exchanger would be a good route to take if your furnace is fairly new.
Even worse, a cracked heat exchanger can be a safety hazard. For instance, if natural gas is leaking from the heat exchanger, it can create a fire or explosion hazard. It can also potentially cause carbon monoxide leakage and build-up, which can be quite dangerous.
Symptoms such as inconsistent water temperature, reduced hot water supply. Unusual noises, rapid pressure increase, and failure of radiators to heat up can all point to a blocked heat exchanger as the underlying issue.
Most homeowners spend between $2,500 and $10,000. Replacing an oil furnace costs anywhere from $2,500 to $10,000, but most people pay $5,000 on average. Understanding the factors that influence the oil furnace replacement cost is essential for making a well-informed decision.
Heat exchangers can be very difficult to repair, and in many cases, a replacement is recommended. If your manufacturer's warranty has expired (or was voided due to lack of maintenance), the part and labor costs of a heat exchanger replacement will likely be far too expensive.
Were you recently told that your furnace heat exchanger is cracked and needs to be replaced? If so, here's the thing: replacing a heat exchanger isn't as simple or affordable as it sounds. In fact, replacing a furnace heat exchanger can take up to 8 hours and can cost anywhere from $3,000 to $5,000.
You should expect to spend between $3,800 and $12,00 on a new furnace, including both the unit and installation costs. Factors influencing the price include the type of furnace (gas, electric, or oil), the unit's efficiency rating, and the complexity of the installation.
Because replacing a heat exchanger can take up to eight hours or longer, it represents the bulk of the cost. If your warranty is expired, and you would need to pay both parts and labor for a new heat exchanger, look further into whether a full unit replacement would be more advantageous for you.
Replacing Your Entire Furnace
Cracked heat exchangers typically occur in furnaces that are more than 15 years old, and the exchanger has been weakened over time due to corrosion. Even if the exchanger is replaced, an old furnace will soon need additional repairs or even full replacement.
Installing a bypass on the heat exchanger is one of the most efficient solutions for its control and operability. Typical process heat exchangers equipped with bypass for control of heat recovery are the feed-effluent heat exchangers (FEHE) used for pre-heating reactors or distillation column feed.
Soot can collect when combustion is incomplete. This can be caused by burners that are improperly adjusted or a cracked heat exchanger. A faulty heat exchanger will produce a strong and unpleasant odor that smells similar to formaldehyde.
Carbon monoxide poisoning is the most serious risk posed by a damaged or failed heat exchanger. Carbon monoxide poisoning can knock someone unconscious, or even kill them.
However, a high-pitched rattling before your furnace kicks on might indicate a cracked heat exchanger, a more serious problem that may require replacement.