Posted in hvac systems and tagged bad heat exchanger, can cracked heat exchanger cause fire, carbon monoxide myths, co poisoning from gas furnace, cracked eyelet heat exchanger, cracked heat exchanger cost, cracked heat exchanger flame rollout, cracked heat exchanger repair, cracked heat exchanger symptoms, cracks in furnace combustion chamber. What causes a heat exhanger in a furnace to crack and fail. A heat exchanger acts as a collection station for combustible gas and allows the gas to make the air reach a boiling hot temperature. The extra air will cause the oxygen reading to change notably. The professional recommendation for a cracked heat exchanger is often a full system replacement. I show how a furnace reacts when there is a crack in the heat exchanger. A cracked heat exchanger is one of the most serious issues that your furnace can develop.
Believe it or not, cracks can develop in most furnaces after years of normal use. The cause can be improperly adjusted burners or a cracked heat exchanger. How can you tell if a cracked heat exchanger is the issue. If these components break or wear down, pressure can fluctuate to a level that the heat exchanger is unable to tolerate. It is, therefore, vital that you have your heat exchanger regularly maintained so that potential problems are addressed before they get worse. Furnace with a cracked heat exchanger and flame rollout youtube. A heat exchanger is made of thin metal, and as it heats up from the combustion of the furnace, it transfers the heat to the air being distributed through the house by the blower 3. Over time, this stress creates cracks in your heat exchanger. More commonly, the cause of a cracked heat exchanger is misapplication or poor maintenance of the furnace. When you suspect the system may have an exchanger leak you can place a manometer probe in the exchanger and seal off the inletoutlet of the exchanger as best you can with the gas shut off obviously. Overheating causes nearly all premature heat exchanger cracks.
A heat exchanger crack in a residential furnace large enough to cause trouble usually upsets a steady flame or causes the burner flames to roll out the front of the. When a furnace is oversized, a number of problems can exist including short cycling and cycling on limit. Next, turn on the blower and see if there is a change in the exchanger. What are the causes of a cracked heat exchanger in a gas.
What caused my heat exchanger to fail check out these real. Read our blog to learn what to do if this happens to you. Sometimes it is a design issue, sometimes it can be attributed to poor maintenance. All too often, furnaces are massively oversized or used incorrectly which causes the heat exchanger to fail prematurely. Heating and air conditioning contractors rarely find furnaces with cracked heat exchangers. Sep 18, 2019 causes of cracks in the heat exchanger. Mar 11, 20 more commonly, the cause of a cracked heat exchanger is misapplication or poor maintenance of the furnace. This is because air is leaking through the crack in the heat exchanger into the combustion chamber.
What causes a cracked heat exchanger on my furnace in eden, nc. This trips a safety switch and shuts down the furnace. If the heat exchanger is cracked, the oxygen reading will change a lot when the blower turns on. The most preventative and cheapest to avoid cause of a cracked heat exchanger is a dirty air filter. Dec 03, 2018 heat exchanger cracks are worth finding but they arent the most dangerous issue for your customers in most cases. In the winter months, we see an abundance of claims involving cracked heat exchangers. A furnaces heat exchanger uses some type of fuelair mix to burn inside of it, creating heat and getting very hot. The heat exchanger on a furnace is the section that keeps the combustion chamber and the breathing air separate 3. A combustion analyzer gives us co and oxygen readings. May 20, 2016 what causes a heat exhanger in a furnace to crack and fail. These coils are contained within an airtight combustion chamber. If the furnace isnt getting sufficient airflow, the exchanger gets too hot and literally cracks under the pressure of continual expanding and contracting.
When a furnace cannot get enough airflow, the heat exchanger overheats and suffers excess stress from expansion and contraction. Heat exchangers sometimes crack as the result of years of regular use. This is usually the result of insufficient airflow which is an issue that crops up when routine maintenance isnt performed. As the interior of the furnace accumulates lots of dust, dirt, and other debris, the filter gets blocked, and clogs.
A crack in your heat exchanger is no trivial matter. The american gas association has even put this in writing they say any visible crack or hole is reason for requiring replacement of the heat exchanger or furnace. The air passes over absorbing heat off the surface conditioning it to warm air. All too often, furnaces are grossly oversized or used incorrectly which causes the heat exchanger to fail prematurely. Heres why your furnace heat exchanger cracked heating. The reason i make this blasphemous statement is twofold. Heat exchanger cracks are worth finding but they arent the most dangerous issue for your customers in most cases. The cause of cracked heat exchangers avoid this common scam.
Causes of a cracked heat exchanger now that weve covered some common symptoms concerning a heat exchanger with a crack in it, lets get into some of the likely causes. A cracked heat exchanger might allow products of combustion to enter the air stream. What causes a cracked heat exchanger on my furnace in eden. This makes the problem easier for a skilled hvac technician to identify during a furnace inspection. The top three causes of loss are age related wear and tear, lack of maintenance, and improper installation. The heat exchanger is a set of coils or tubes inside the furnace that is responsible for heating the air in your home. In furnaces, the heat exchanger is designed to direct combustion byproducts to the exhaust flue on one side and warm air into the house on the other.
If you experience these symptoms only when youre at home and the. Older furnaces can develop major issues, such as a cracked heat exchanger. Dec 28, 2016 a furnaces heat exchanger uses some type of fuelair mix to burn inside of it, creating heat and getting very hot. What caused my heat exchanger to fail check out these. A cracked heat exchanger is pretty serious, as far as safety for your home goes. Corrosion andor cracks on other furnace components when other external parts of your furnace start showing signs of wear and tear, its highly possible that the internal parts are also beginning to wear.
Causes of cracked heat exchangers aaction air conditioning. Beware of an unethical technician who finds a crack with a camera on a furnace that seems to be running just fine. Home warranties and cracks in your furnaces heat exchanger. A professional preseason furnace inspection can help determine if your heat exchanger is cracked. Overheating is the most common cause of a cracked heat exchanger.
For this reason, it is essential for property adjusters to understand the function of a heat exchanger and to know when to seek the help of experts. I open up the plenum and show the crack from the top. Dec 30, 2019 the heat exchanger is cracked or otherwise has an air leak. From what ive been told and read, it could mean that my heat exchanger is cracked. If a crack makes its way through the walls of your heat exchanger, dangerous carbon monoxide fumes can leak into your homes air. Signs and symptoms of a cracked gas furnace heat exchanger. Nowadays, checking for a cracked heat exchanger is way more scientific.
Gas furnace pressure switch problems gray furnaceman. The first step is simply to look where most homeowners cant. Combustion gases leaking from a cracked heat exchanger can cause frequent headaches as well as flulike symptoms. In essence, it separates the airstream from the fire. The american gas association has even put this in writing they say any visible crack or hole is reason. What are some tell tale signs of a cracked heat exchanger. A blockage in the vent will also cause a pressure switch to not close. Its the most common cause of excess carbon monoxide in a home. Cracked heat exchangers are commonly caused by overheating.
The most common reason a heat exchanger cracks is normal wear and tear. Theres a lot of good info on there, but some of it is misleading and there are a lot of straw man arguments made. If there is a crack in the furnaces heat exchanger, there will be some signs and symptoms that are normally evident concerning the furnace. One of the best ways you can protect your home from the dangers of a cracked heat exchanger is to know how those cracks develop in the first place.
Gas burns in the burner, and the heat from the flame is passed into a metal coil known as the heat exchanger. In the video above the furnace techs says the oxygen reading could rise as high as. As air flows past the outside of the heat exchanger, the air becomes warm. The burner ignites the gas that enters the heat exchanger.
A crack in the heat exchanger could also be at fault. Cracked heat exchanger deciding to repair or replace. When a heat exchanger becomes damaged and the combustion fumes and gases mix with the clean air. Cracked heat exchanger deciding to repair or replace depending on the age of your furnace, a cracked heat exchange probably means you need a new system. Oct 19, 2017 how the pros identify a cracked heat exchanger.
This problem is often avoidable with regular and diligent heater maintenance. Over time, the heat stress causes cracks near weak areas such as bends or welds. Theres something wrong with how the system is combusting gas. However, given the highstake dangers associated with carbon monoxide inhalation, the general recommendation from the cdc is to deal with potential sources of this gas as soon as possible. Co is produced as a result of incomplete combustion. A heat exchanger is the metal component in a furnace that allows for heat transfer. If your heat exchanger has cracks, these cracks cause your furnace to perform inefficiently. Furnace with a cracked heat exchanger and flame rollout. However, the cracks need to be fairly large to cause a significant co leak.
As the heat exchanger warms, the blower or fan motor forces air across it. We use it to check co levels given in parts per million, or ppm and determine for sure whether theres a crack in your heat exchanger. Water in the vent due to a sag in the piping could cause a pressure switch not to close. You can do your part to prevent cracks from forming in your heat exchanger by understanding the root causes of these cracks.
A cracked heat exchanger can also be the result of a worn control valve. In some rare cases, it can cause flame impingement when air from the blower enters the heat exchanger. Cracked heat exchangers, causes and solutions what is a heat exchanger. Another warning sign of a cracked heat exchanger is unusual sounds from the furnace, such as rattling or clicking. This issue causes pressure changes that the heat exchanger cannot handle. Combustion pollutants, such as carbon monoxide, nitrogen dioxide and sulfur dioxide, can cause eye and nose irritation, disorientation, sleepiness and nausea. Many heat exchangers crack simply because they are old. When a furnace cannot get enough airflow, the heat exchanger overheats and. If air isnt moving through the system, too much heat will be left in the heat exchangers chamber, causing its coils to overheat.
There is a possibility that those poisonous gasses from your burners could leak into the air being blown throughout your home. Dec 02, 2015 a cracked heat exchanger allows air from the furnace blower to interfere with the flame causing it to flutter or even roll out. Issues brought about by a cracked heat exchanger bring inconveniences to you as a. Located in the center of the furnace, it is where fire, gas and heat connect. These dangerous gases can cause illness, or in extreme cases, death. What are the causes of a cracked heat exchanger in a gas furnace. This makes it essential to have your furnace regularly inspected so that the potential for developing issues can be identified and dealt with. When it comes to a cracked heat exchanger, dont panic. These two words are nomenclature meaning the thin layer of metal that separates the good air that you breathe and the bad air comes from burning natural gas in a forced air heater or burning propane in a forced air heater. Carbon monoxide exposure also causes death, which is why cracked heat exchangers are such a serious problem. Due to the nature of what causes a cracked heat exchanger, which can include an oversized furnace, or a unit close to its life expectancy, the cost of a replacement could eclipse the that of a new system. If air isnt moving through the system, too much heat will be left in the heat exchangers chamber, causing its.
A cracked heat exchanger allows air from the furnace blower to interfere with the flame causing it to flutter or even roll out. At its outset, a cracked heat exchanger is a problem that will go unnoticed by most homeowners. Proper airflow through the heating system is essential for several reasons one is to keep the heat exchanger from overheating. Many heat exchangers are at a negative pressure in reference to the air moving over the exchanger. The heat exchanger is a key part of the furnace and is responsible for the actual heating of air.
However, professional hvac technicians always check heat exchangers for damage during their preseason maintenance inspection. Any change is an indication of a heat exchanger leak. The most common cause of an overheated heat exchanger is as simple as a. Jan 21, 2019 the heat exchanger is a set of coils or tubes inside the furnace that is responsible for heating the air in your home. Nov 05, 2019 what causes a heat exchanger to crack. If its cracked, it may allow potentially lethal carbon monoxide co and other combustion byproducts into your homes airstream. Jan, 2020 a heat exchanger acts as a collection station for combustible gas and allows the gas to make the air reach a boiling hot temperature. Jan 10, 2018 gas burns in the burner, and the heat from the flame is passed into a metal coil known as the heat exchanger. It is important that the heat exchanger is taken care of as hazards can build from a faulty exchanger. The main reason why a heat exchanger becomes cracked is due to the unit overheating.
If theres a crack in this component, the gases being burned off, such as carbon monoxide, sulfur dioxide, and nitrous oxide, could leak into your home, causing illness or, in extreme cases, death. Ice on the venting or a plugged screen on the vent termination only on 90% efficient furnaces could also be the problem. Carbon monoxide leaks are difficult to detect, which is why we advise homes with gas appliances have co detectors installed. Incomplete combustion usually causes an increase in soot. When the the cycle stops, i dont hear any hissing after which could mean water leaking out of the exchanger. But the decision to repair or replace a heating unit can be difficult. Thanks for watching guy browns youtube channel was. Watch for the following specific signs pointing to cracks in your heat exchanger.
For this reason, i want to share with you some of the common symptoms and causes of a cracked heat exchanger in a furnace. A cracked heat exchanger is not a problem that should be taken lightly. Heat exchangers are made of metal that expands and contracts every time your furnace turns on and off. Your blower motor aka your fan then blows air over this heat exchanger. A cracked heat exchanger can cause combustion byproducts like carbon monoxide to mix with the air being circulated into the house. Furnace heatexchanger crack signs your furnace has one. The heat exchanger is cracked or otherwise has an air leak. A cracked heat exchanger can cause combustion byproducts like carbon monoxide to. The materials used in the construction of the heat exchanger will expand and contract numerous times over its lifespan.
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