What is one of the signs of a bad heat exchanger?

Author: Mrs. Precious Quitzon  |  Last update: Sunday, April 13, 2025

Immediately call an HVAC professional to assess your furnace if you notice any symptoms of a bad heat exchanger:
  • Orange, yellow, or flickering burner flames.
  • Pungent smells.
  • Rattling, popping, or banging sounds.
  • Carbon monoxide detection.
  • Corroded or damaged components.

Will a furnace run with a bad heat exchanger?

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.

What is the average cost to replace a heat exchanger?

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. However, it is not worth spending your money on replacing your heat exchanger when it is near the end of its life span, which is ten years or more.

What is the life expectancy of a furnace heat exchanger?

In the past, heat exchangers were often built with heavy metals, such as cast iron. These exchangers can last as long as 30 or 40 years, much longer than the steel exchangers most manufacturers build today. Modern stainless or aluminized steel heat exchangers typically have a life span of 15 to 25 years.

How can I tell if my heat exchanger is bad?

Immediately call an HVAC professional to assess your furnace if you notice any symptoms of a bad heat exchanger:
  1. Orange, yellow, or flickering burner flames.
  2. Pungent smells.
  3. Rattling, popping, or banging sounds.
  4. Carbon monoxide detection.
  5. Corroded or damaged components.

Watching A Furnace Run With A Cracked Heat Exchanger

Is it better to replace a heat exchanger or a new furnace?

Furnaces have an average lifespan of around 10 years, and most exchangers tend to go out around this time. If your furnace is close to this 10-year mark, a new furnace is likely a better investment. If your furnace is relatively new, a new heat exchanger may be worth it to avoid early furnace replacement.

How much does it cost to replace a heat exchanger?

The good news here is that a heat exchanger can be replaced, however, the actual cost of replacing a heat exchanger is at least £500, especially for top brands like Worcester Bosch, Viessmann & Ideal.

Can you fix a furnace heat exchanger?

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.

What is the most reliable gas furnace brand?

The 5 Best Furnace Brands
  • Carrier Furnace: Best Warranty.
  • Lennox Furnace: Best Company Reputation.
  • Bryant Furnace: Best for Durability.
  • Trane Furnace: Most Years of Experience.
  • Amana Furnace: Best for Efficiency.

How can a heat exchanger be examined for damage?

There are signs that a technician can look for that might indicate if the heat exchanger is damaged, without having to examine the bottom of the exchanger itself. These signs might include: A build-up of soot and ash within the furnace. Development of rust of the heat exchanger.

How to clean a furnace heat exchanger?

The Heat Exchanger Block
  1. Turn off the furnace. As with all the previous furnace cleaning procedures, you first want to turn off the unit and disconnect it from all power sources. ...
  2. Brush off dirt stuck to the block. ...
  3. Vacuum the chambers of the heat exchanger block. ...
  4. Finally, remember to put the furnace back the way it was.

How do heat exchangers fail?

A large majority of heat exchanger components fail by way of fatigue, creep, corrosion, oxidation, and hydrogen attack. Most common causes of failure include fouling, scaling, salt deposition, weld defects, and vibration. Effective recommendations to prevent such failures form an important part of this study.

Can I replace a heat exchanger myself?

And remember, trying to replace a heat exchanger without professional assistance can pose potential hazards such as carbon monoxide poisoning and other safety risks.

How do you know if you have a blocked heat exchanger?

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.

How much is a new furnace?

Ask twenty professional HVAC contractors the question, “How Much Does A New Furnace Cost?” and you'll probably get the same answer... “It depends.” On average, the cost of a new furnace can range from $2,000 - $14,2001. However, factors like furnace efficiency, type, size, and much more can impact this range.

How many hours does it take to replace a heat exchanger?

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.

How to estimate the cost of a heat exchanger?

The popular method is to use the cost per area of the heat exchangers which is determined using an overall heat transfer coefficient U from A =Q/UΔT m but the challenge with this method is that obtaining the heat exchanger areas can be complex.

Can you bypass a heat exchanger?

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.

How do I know if my heat exchanger is bad?

Signs of a bad heat exchanger in a gas furnace include strange noises, a yellow or flickering burner flame, increased fuel bills, carbon monoxide detector alarms, and unusual odors, such as a burning smell or the scent of exhaust fumes.

Can you run a furnace with a bad heat exchanger?

Rule #1: If your Heat Exchanger has been deemed cracked by a HVAC professional you should NOT be running it. Unfortunately, some owners will attempt to run their furnace even when a cracked heat exchanger has been detected.

How long should a furnace last?

What is the average life of a residential furnace? A furnace that receives regular maintenance can last at least 15 to 20 years, but completing annual maintenance and being diligent with repairs can extend the life of a furnace even longer.

How much is labor to replace a heat exchanger?

It can range between $1,000-$4,000 for parts and labor, with an average cost of $2,000. Learn how this heat exchanger cost breaks down and how to identify the crucial signs it's cracked and needs replacement.

What is the most expensive part of a furnace to replace?

Identifying the Priciest Component: The Heat Exchanger

Due to its complex role, a failure or crack in the heat exchanger can lead to serious issues, including dangerous carbon monoxide leaks. This makes furnace repair essential to maintain safety and functionality.

What is the Trane heat exchanger lawsuit?

Consumers filed the Trane defective AC class action lawsuit alleging that some Trane and American Standard air conditioners contain unapproved rust inhibitors. This reportedly causes sticky deposits to form in and clog the thermostatic expansion value (TXV), which can in turn, cause the air conditioners to fail.

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