furnace heat exchanger replacement cost

Average Cost of Furnace Heat Exchanger Installation

You can expect to pay around $815 for replacement when in warranty and around $1,950 when the furnace is out of warranty. Keep in mind a warranty only covers the cost of parts and not the labor to install a heat exchanger.

Note: There is no way to repair a cracked heat exchanger in your furnace. It must be replaced, or the entire furnace needs to be replaced. If the furnace is more than 8 years old or the replacement is no longer in warranty, it’s best to get furnace replacement quotes at the same time.

In most cases an HVAC contractor will remove the old heat exchanger and replace with new parts. They’ll restart the furnace to assure it’s working properly, then cleanup the work area and dispose of all old parts or return to the manufacturer if required by the warranty.

Average Do It Yourself cost

$420 (Not recommended)

Average Contractor Installed Cost

$815 – $1,970

Typical Cost Average


Last Updated: Wednesday, January 12, 2022

Overview of a Furnace Heat Exchanger

The most common type of heat exchanger is a series of hollow, ribbon-like tubes that combustion gases pass through on their way out of the furnace through the flue vent. It transfers heat into air being circulated past the heat exchanger and into your home’s ductwork. High-efficiency furnaces, also called condensing furnaces, have primary and secondary heat exchangers to make more complete use of the heat produced.

A damaged, leaking, or cracked unit can allow dangerous carbon monoxide to leak gasses into the airflow, and thus spreading the odorless CO gas into your home along with the warm air.

Heat exchangers are at the very core of a gas furnace. To replace it requires disassembling much of the furnace, replacing the part, and reassembling the furnace. This is a lengthy process, so labor charges make up most of the replacement cost – all of it when the part is under warranty.

Note: In nearly all cases, if your furnace is more than 12 years old, it makes more sense to pay to have the entire furnace replaced versus attempting to repair this part. Learn more about gas furnace costs.

Repair Cost Details

Heat Exchanger Replacement Part Factors

There are no cheap or easy ways to repair a cracked or failed heat exchanger, but some are costlier than others. Here are the factors that affect the cost of the replacement part.

  • Furnace Size – The size is based on the BTU capacity of the furnace. The larger the furnace, the larger and more expensive the heat exchanger.
  • Heat Exchanger Type – Older furnaces with ribbon exchangers are much more affordable than newer high efficiency furnaces with secondary heat exchangers.
  • Furnace Design – Some furnace were designed with making repairs easier in mind. This will save several hours on the repair at $70 to $135 per hour for labor costs.
  • Furnace Efficiency – High-efficiency furnaces are more complex and more expensive than 80% furnaces.
  • Furnace Location – Making the replacement on a furnace that is easy to access is difficult enough. When the furnace is in an attic or crawlspace, very few contractors will agree to replace the heat exchanger. If they do, estimates might exceed the cost of a new furnace.
  • Material – Stainless steel units cost more than other steel types.
  • Where you Live – The cost of living varies across the country and affects furnace repair too.

Replacement Considerations

Labor isn’t covered in the warranty! Heat exchangers come with great warranties, usually 20 years or lifetime. But the warranty is for just the part. Many homeowners don’t realize that labor charges ARE NOT included in most repairs beyond the first year, even when the part is under warranty.

Furnace replacement warranty? Warranties are getting more competitive. Many brands back their better furnaces with a warranty that provides for complete furnace replacement if a major part like this fails in the stated time period. For most, the warranty is for 3, 5 or 10 years. A few, like Amana, have a lifetime furnace replacement warranty on this integral part of your system. Check your warranty coverage. Even if you have to pay to have the replacement furnace installed, the cost probably won’t exceed the labor cost of heat exchanger replacement.

Repair or replace? When you get repair quotes, you should also ask for estimates for replacing the furnace. Apart from cost alone, you might want to replace the furnace if:

  • It is more than 10 years old
  • Doesn’t properly heat your home
  • You prefer a furnace with higher efficiency and/or better indoor climate control features

Beware of Scams! While most furnace contractors are honest, you might run into one trying an old scam – telling you the heat exchanger is cracked and leaking carbon monoxide into your home, and the entire furnace must be replaced. This scam is usually attempted during routine furnace maintenance or when another repair is being made.

Unless your carbon monoxide detector going off was the reason you called for furnace repair, it is always a good idea to get a second opinion on this issue. Inspectapedia has a great page detailing all the ways that this part can be tested, as well as preventative maintenance tips to assure you get the most from your furnace.

Cost of Installation Supplies

  • $115 – $950 | Galvanized or aluminized steel heat exchanger.
  • $875 – $1,700 | Stainless steel heat exchanger.
  • $15 – $30 | Associated fittings and fasteners needed for the project.

Permits, Inspection, Related Costs and Installation Time

Permits and Inspection Cost

Whether a permit is required varies by location. The benefit of getting a permit is that an inspection will be made to ensure the work is done properly and your furnace is safe to use. The disadvantages are cost and having to wait for the inspection, which means you’ll be without heat longer.

You can call your local building code department to find out. It’s possible a local contractor might tell you a permit is not required when it actually is. The repairman might not want to wait for the inspection, preferring to do the work, get paid and move on.

  • $0 – $150 | Permit fees, when required.

Related Costs and Installation Time

Labor costs have been factored into the costs in the table at the top. However, in case you’re wondering, labor rates for certified technicians range from about $70 to more than $125 per hour. If a helper assists the technician, rates are $25 to $50 per hour.

Install Time Schedule

Replacing this part on your furnace is the most time-consuming repair. Spending 8 hours on the project is not unusual.

  • 5 to 3 hours | Disassembling the furnace and removing the part
  • 1 to 2 hours | Installing the new replacement part
  • 2 to 3 hours | Reassembling the furnace and testing it

Is it Covered Under Homeowners Insurance or a Home Warranty?

Homeowners Insurance Coverage

We have never seen or heard of a cracked heat exchanger being covered under homeowners insurance policy. In cases where a furnace would be replaced, they would replace the entire unit versus a single part inside.

Home Warranty

If you have a home warranty that covers major repairs, this might be covered in full or partially, and it’s worth your time to discuss it with your carrier. Landmark Home Warranty says that as long as you had coverage during the time the crack was located and proper maintenance was taken since your coverage, you will be covered.

DIY or Hire a Pro?

Replacing a this part on your gas furnace is a complex, difficult job. It requires taking apart the furnace, keeping track of your steps, and then putting it back together in working condition. There’s also a HUGE risk. Doing the job incorrectly may allow carbon monoxide to leak.

For these reasons, we can’t recommend it. In fact, pro replacement probably isn’t a good idea either unless the furnace is less than 10 years old and the part is under warranty. It is usually a better idea to replace the furnace, especially if it is old or you’re not happy with its performance.

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