Can You Repair a Cracked Heat Exchanger on a Gas Furnace? It is Worth the Cost?

red tagged heat exchanger

One of the most common reasons a gas furnace can be taken out of service, is when the repair technician finds to a cracked heat exchanger.

The furnace heat exchanger is the one of the main components inside the gas furnace and it’s used to transfer the heat from the gas burner to the warm air that’s blown into your home. When a gas furnace heat exchanger fails, not only is it dangerous and can result in carbon monoxide poisoning, the heat exchanger replacement cost is usually on the high side of typical furnace repair costs.

In this Gas Furnace Guide article, we’ll take a look at how hard it is to replace the heat exchanger in a gas furnace, and help you decide if it’s even worth replacing, due to age of your furnace, price of a new heat exchanger, and the labor to install it. In many cases, the cost to replace just the furnace is not much more than replacing the heat exchanger itself.

Dangers of a Cracked Heat Exchanger

Before you consider running your furnace with a cracked heat exchanger, you should know that it can be very dangerous, and if the cracks are large or there are actual holes (like swiss cheese), it could be deadly and you need to take it very seriously! This is one of those times that you want to error on the side of safety, its worth it! Read more about Carbon Monoxide Tips and Safety, and general Gas Furnace safety tips.

  • CO is not CAUSED by a Crack in the Heat Exchanger. Carbon Monoxide is the result of unburned fuel, not the heat exchanger.
  • Cracks can release CO (Carbon Monoxide) into your home.
  • The cracks DO NOT get better, eventually, it MUST be replaced.

The safety factor is why most heating contractors handle it like they recently did with Ally Bean of The Spectacled Bean. The heating contractor will place a red-tag on your furnace, disconnect the power and natural gas service, and report it to the gas company when they find cracks. Most often, they want to cover their own butts, and make sure they fault on the side of safety.

In some cases, less than professional heating contractors have used this as a tool to pressure homeowners into buying a new furnace, so it’s important that you never settle for one opinion. Unless you have a long-standing trustworthy relationship and have complete confidence in the heating contractor, always get a second opinion before you agree to let the anyone do any work on your system. Get free repair quotes from local qualified contractors.

What’s Covered Under Warranty

Many gas furnace brands have a heat exchanger warranty that lasts the life of the system. This will usually cover the cost of the heat exchanger part itself, and may include some of the other parts that may need to be removed in order to replace the heat exchanger.Your heating repair contractor will have to handle the warranty claim with the manufacturer, and get the replacement parts from the factory or part supply house if they are available.

The main issue with warranties like this is that in order to replace the heat exchanger, you have to disassemble the entire gas furnace and the cost of labor to do it, is going to be very high. (View common furnace repair costs) After you get the new heat exchanger installed, you still have an old furnace that is bound to fail again very soon.

Replacement Versus Repair

When you hear that you will still have to cover $1200 of labor to replace the heat exchanger, its worth your time to make sure you get a furnace replacement estimate. You may find that for not much more money, you can get a new, higher efficiency furnace that will provide much higher return on your investment, and may even quality for tax credits.

When to Consider Repairing the Heat Exchanger –

  • Furnace is less than 10 years old
  • 100covered by manufacturers warranty
  • Repair cost is less than 25of the replacement cost

When to Replace the Furnace –

  • Furnace is more than 7 years old
  • Furnace is low efficiency
  • Damage is beyond repair
  • You have already gotten at least 2 second opinions.

Read more about deciding when to replace or repair your gas furnace to get a better idea of the cost factors involved with owning an old unit.

Share Your Experience

Have you recently had your furnace red-tagged or been told you need to replace your furnace heat exchanger? Did you have your heat exchanger repaired by a local contractor? If so, please consider sharing your experience below, it will help future readers faced with the same issue.

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One Response to “Can You Repair a Cracked Heat Exchanger on a Gas Furnace? It is Worth the Cost?”
  1. Christopher says:

    Our 20+ year old Trane furnace was recently shut off because of a bad heat exchanger. The tech quoted us $950 for a new xb80 heat exchanger, plus an additional $300 in other parts. We decided to replace versus repair and the new furnace cost us $2900, 92afue, installed.