how do i know if my furnace heat exchanger is bad

Signs Your Heat Exchanger Is Cracked

Full Answer

What are the signs of a broken furnace heat exchanger?

The heat exchanger of your heating system may be cracked if it produces a strong and unpleasant smell. A significant characteristic of the fumes is that they typically smell like formaldehyde; they are incredibly toxic when inhaled. A formaldehyde-like odor is indicative of a broken furnace so contact a professional HVAC contractor today.

What causes a heat exchanger to go bad?

A common cause for a bad furnace heat exchanger is a dirty air filter. When the filter in your furnace gets dirty or clogged, it restricts airflow. When air can’t flow through the furnace properly, the furnace overheats the exchanger, resulting in cracks from too much pressure.

What does a cracked heat exchanger smell like?

If your heating system produces a strong and unpleasant smell, it could be that the heat exchanger has cracked. Notably, the fumes usually smell like formaldehyde and are highly toxic to your body when inhaled.

Can a cracked heat exchanger cause odd behavior in a furnace?

Odd Furnace Flame Behavior When you have a cracked heat exchanger, you will have combustion air from inside your furnace that is mixing with the air going into your home. The combination of these two things will change the behavior of your furnace flame. This is once again when you may want to bring in a furnace technician.

How do I test my furnace heat exchanger?

0:152:22Simple Furnace Heat Exchanger Test | Lennox Learning SolutionsYouTubeStart of suggested clipEnd of suggested clipAnd easiest ways to test them while it's true we can disassemble the heat exchanger take theMoreAnd easiest ways to test them while it's true we can disassemble the heat exchanger take the manifold. The burners out and do a visual inspection.

Will a furnace run 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.

Is it worth replacing furnace heat exchanger?

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.

How long does a heat exchanger last in a furnace?

While heat exchangers are typically manufactured to last between 10 – 20 years, many factors can accelerate the process of heat exchanger failure. These factors usually fall under the categories of poor maintenance, poor initial system design and installation, or poor equipment design by the manufacturer.

How do I know if I need a new heat exchanger?

Limescale Buildup. One problem commonly associated with the heat exchanger is a buildup of limescale. ... Kettling and Whistling Noises. ... Leaky Boiler Heat Exchanger. ... How to Resolve a Limescale Buildup. ... Central Heating Sludge. ... Faulty Boiler Heat Exchanger. ... Yellow or Distorted Burner Flame. ... Leaking Water.More items...•

What happens when a heat exchanger goes bad?

The heat exchanger is a conglomeration of tubes/coils in your furnace where the air is heated. A crack in your heat exchanger can be bad news for you, your furnace, and your home if you don't act fast. This causes carbon to be burned, which can release nitrous oxide, sulfur dioxide, and carbon monoxide.

What are the common failures in heat exchanger?

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.

How much does it cost to change a heat exchanger?

The average costs for replacing your exchanger is about $1,500. However, it can cost as little as $500 or as much as $3,500. If the heat exchanger is cracked or malfunctioning before you would typically expect it, there may be another issue with your HVAC system.

What causes a heat exchanger to fail?

Dirty air filters are one of the most common causes of heat exchanger failure. This is because a clogged filter will restrict airflow, causing the exchanger to overheat and suffer excess expansion and contraction stress.

What maintenance is required on a heat exchanger?

To keep the heat exchanger in good condition, regular maintenance is required. In addition to cleaning plates on a regular basis, gaskets must be replaced as needed to prevent leaks.

Should I run my heat exchanger in the winter?

Optimize air circulation and replace natural ventilation Air exchangers should be run at all time, summer and winter. Depending on the size of your home, energy-efficient air exchangers can cycle through all the air in your home in just a few hours.

Does a heat exchanger need to be cleaned?

Typically, heat exchangers are cleaned every one to three years, depending on the type, size, and service. Keeping heat exchangers free of buildup from sediment, hard water deposits, chemicals, and solids via thorough and proper cleaning improves operational efficiency, and extends the exchanger lifecycle.

Can a cracked heat exchanger cause a furnace to overheat?

The most serious risk of an overheating furnace is stress cracks in the heat exchanger caused by overheating. The vast majority of premature heat exchanger damage is due to overheating as the heat stress causes cracks near the welds and bends.

What are the common failures in heat exchanger?

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.

How important is heat exchanger in furnace?

Every furnace contains a heat exchanger. It's an essential part of the heating process. To create heat, your furnace combusts fuel—typically gas, but other varieties exist—in a sealed chamber. This combustion process generates heat energy from the fuel source.

What might be the problem if the furnace runs but with short cycles?

An overheating furnace can potentially create cracks in the heat exchanger, which can be harmful to your well-being because carbon monoxide can leak into your home. If you suspect this is the reason your furnace is short cycling, it is imperative that you contact an HVAV professional to repair the unit.

How to tell if heat exchanger is bad?

This is once again when you may want to bring in a furnace technician. That is because they can often diagnose heat exchanger problems simply by looking at the flame. If the flame is jumping when the blower fan engages, then there is a sign that your exchanger is bad.

What happens if a furnace heat exchanger goes bad?

When something goes wrong in your furnace heat exchanger, the first sign might be chemical smells. The smell might also cause you to have headaches or nausea. Harmful chemicals are in your home at this point, and it is important to seek immediate help.

Why is my heat exchanger cracking?

Cracks occur because the heat exchange is exposed to heat over a long period of time. This causes the walls of the heat exchanger to develop cracks. Typically you will find these cracks along the heat exchanger’s seams.

How does a heat exchanger work?

The heat exchanger in your furnace works to separate the combustion process from your breathing air. The exchanger is made of a metal chamber as well as a passageway. It begins at your burner assembly and then ends near where the chimney vent connects to the furnace .

What happens when you retire a furnace?

By the time it is time to retire it, the metal in your exchanger will have been heated up and expanded thousands of times! Alternatively, it will also have contracted when it cooled. This cycle is part of the normal furnace heating process.

What does it mean when your furnace goes bad?

If you see signs of decay, or just wear and tear on the exterior of your furnace, then it has most likely gone bad. It means that your furnace is getting too old to work properly. You may need to replace it.

What does it mean when you see soot on your furnace?

Soot is black in color and is the accumulation of burnt carbon. If this is found on the inside of your furnace, then you know you have a problem. This could also mean you have other problems such as your burners not being adjusted correctly. Both can lead to monoxide production.

What does a malfunctioning heat exchanger smell like?

Strange smells. A malfunctioning heat exchanger will often create an unpleasant and strong odor that smells similar to formaldehyde.

What happens if a heat exchanger is cracked?

If there's a crack in one of the cells of the heat exchanger, the gases being burned – carbon monoxide, sulfur dioxide, nitrous oxide – could leak into your home, causing illness or, in extreme cases, death. Strange smells.

Why does my heat exchanger make a noise?

Because the heat exchanger is made out of metal, as it is heated cracks will expand/contract, and can cause rattling, popping, and/or banging noises. Presence of Carbon Monoxide. Carbon monoxide (CO) is an odorless, colorless, and tasteless flammable gas which is toxic. A failed heat exchanger may leak CO into your home.

What to do if furnace is failing?

If you think your furnace may be failing, or suspect the heat exchanger is damaged, call Your Plumber to schedule an inspection.

Why does my furnace crack?

An over-sized furnace can also cause overheating and crack the heat exchanger. However, the most common reason that a heat exchanger will crack is just normal wear and tear. Heat exchangers, made of metal, go through continuous expansion (as it heats up) and contraction (as it cools). Over a span of time, this will simply cause ...

Why do furnaces need heat exchangers?

Furnaces rely on a heat exchanger to provide warm air throughout your home. It is an essential part of your heating system, and any issues with it will not only lead to a breakdown of your furnace but also pose serious risks to the health and safety of your home. Your furnace combusts gas in a sealed chamber in order to create heat.

Why do heat exchangers need to be air tight?

To work properly and prevent these unhealthy gases from escaping, the heat exchanger must have an air-tight seal to keep contamination away from your breathing air. If you think your furnace may be failing, or suspect the heat exchanger is damaged, call Your Plumber to schedule an inspection.

How to tell if heat exchanger is cracked?

To tell if your heat exchanger is cracked, you will need to look for the signs. If water collects at the base of your furnace, or there’s excesses soot or strong smells coming from your furnace, it’s most likely cracked . Also, if the fire is yellow or there’s any corrosion, you most likely have a cracked exchanger.

What happens if a furnace heat exchanger cracks?

In addition, it is a health hazard that may cause your family to be poisoned by carbon monoxide . By maintaining the furnace regularly, you can prevent this from happening. However, if it cracks, you must replace it immediately.

How Does A Heat Exchanger Work?

When it is cold outside, a heat exchanger in a gas furnace warms the air inside to keep the house warm. Coils and tubes of the system are used to loop constantly and heat the air passing through it.

What happens when a heat exchanger is running?

While your system is running, the return ducts in your home are sucking in cold air and passing it along with the heat exchanging unit. Through ducts, you will receive warm air from the heat exchanger wall once it is heated up. On the other hand, the heat exchanger will emit combustion gases into a vent that channels them outside the house.

Why do heat exchangers crack?

Rusting Of Metals: Moreover, corrosion or rusting are significant causes of heat exchanger cracks. Metals corrode and can cause cracks in heat exchangers if they are exposed to rust. The components of your system can develop cracks if you haven’t maintained them properly.\

Why is my furnace turning yellow?

It can, however, indicate that the burner is dirty or that the heat exchanger has cracked if your furnace produces a yellow flame. If, however, the flame is yellow and also flickers, the chances are high that the furnace has further damage.

How long does a furnace heat exchanger last?

Furnace Age: Heat exchangers of furnaces usually last 15 years. You are likely to find cracks in the heat exchanger if your gas furnace is about that age. It is best to prepare a replacement in case it breaks so that you don’t experience any inconveniences.

What to do if heat exchanger is bad?

There are only two options if a Heat Exchanger is bad: Replace the heat exchanger or replace the furnace. If the heat exchanger is under warranty, this option is a good way to go unless it is unavailable in the time frame needed, which can be immediate in cold weather. The other factors are energy efficiency and cost of service which can make ...

How to replace a heat exchanger?

There are only two options if a Heat Exchanger is bad: 1 Replace the heat exchanger or replace the furnace. If the heat exchanger is under warranty, this option is a good way to go unless it is unavailable in the time frame needed, which can be immediate in cold weather. 2 The other factors are energy efficiency and cost of service which can make replacing the furnace a preferable option even if the furnace is under warranty and available. If a furnace is out of warranty the preferable option is to replace the furnace.

Why do heat exchangers have to have a tight seal?

The heat exchanger must have an air (and gas) tight seal to separate the gasses in the flue products inside the heat exchanger from the breathing air passing over the outside surface. This is because the flue gasses can be poisonous – such as deadly carbon monoxide – and contamination of the breathing air by these gasses pose a health risk ...

Why is CO a symptom of bad combustion?

A furnace creating CO is a symptom of bad combustion in a furnace because unlike a car, CO is not a regular by-product of the furnace combustion process. Therefore, a heat exchanger can be breached and if the furnace is not producing carbon monoxide the breach will remain undetected. 6.

How long do heat exchangers last?

While heat exchangers are typically manufactured to last between 10 – 20 years, many factors can accelerate the process of heat exchanger failure. These factors usually fall under the categories of poor maintenance, poor initial system design and installation, or poor equipment design by the manufacturer.

What is the visual inspection of a heat exchanger?

A heat exchanger must be visually inspected on a regular basis. Visual observation of light or water passing through the breach is positive confirmation of a crack or hole in a heat exchanger.

Why is Vincent's willing to risk a free furnace?

The reason that Vincent’s is willing to put up such ‘high stakes’ is because of the confidence in their equipment and their procedure.

Why is my furnace blue?

A typical furnace flame should be blue. If your furnace produces a steady blue flame, it’s clear that the furnace’s heat exchanger is functioning efficiently, and there’s nothing to worry about. However, if the furnace produces a yellow flame, it can mean that your burner is dirty or your heat exchanger has cracked.

How much does it cost to replace a heat exchanger?

To replace a new heat exchanger, you need around $600-$1,200 to buy and install the replacement. So, fixing a new heat exchanger in an old furnace will not be worth the price. Otherwise, the furnace can break down when the heat exchanger is still new.

What happens when you heat a home with gas?

Heating your home with natural gas, propane gas, or fuel oil can result in the leakage of harmful gases when the heat exchanger cracks. Fossil fuel gases like carbon monoxide and carbon dioxide can cause several health issues.

Why does my furnace have water on the floor?

Water Collects on the Floor around the Furnace. If your furnace doesn’t have any condensation issue and you find some water on the floor at its base, the chances are high that the heat exchanger is the issue. You’ll need to contact a professional HVAC contractor to determine the root cause of the problem.

What happens when a furnace ignites?

When ignited, the furnace will channel hot combustion gases into the heat exchanger chamber to heat the metal walls. Meanwhile, return air ducts in the system will suck the cold air in your home and pass it along the heat exchanger to warm up the air.

Why does my heating system smell so bad?

The System Produces a Strong Smell. If your heating system produces a strong and unpleasant smell, it could be that the heat exchanger has cracked. Notably, the fumes usually smell like formaldehyde and are highly toxic to your body when inhaled.

What is a heat exchanger?

A heat exchanger is one of the components in a gas furnace that heats air to warm your home during cold days. The system comprises a series of coils and tubes that consistently loops to heat air that flows through it.