Another heat exchanger killer is airflow, or more specifically, a lack of it. If there is a crack in the furnaces heat exchanger, there will be some signs and symptoms that are normally evident concerning the furnace. Furnace location making the replacement on a furnace that is easy to access is difficult enough. Listed below are a few of the signs to look out for is you think your heating system might have a cracked heat exchanger. If the oxygen reading rises to abnormal levels once the lower turns on, this is because the blower is pushing air into the combustionchamber through the crack in the heat exchanger. Furnace with a cracked heat exchanger and flame rollout. Any change is an indication of a heat exchanger leak. Before you can do any repairs, you should make sure that you check over your furnace heat exchanger thoroughly. Because this is such a hot button topic dont take my word for.
Now remember, this does not hold true if the crack is way up in the heat exchanger. Broken and leaking heat exchangers are responsible for about 1,500 deaths per year in the united states, and many more people are poisoned by exposure to toxic gasses that go unfiltered by defective heat exchangers. 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. This video is about the your heat exchanger is cracked so your furnace must be replaced scam. Jan 10, 2018 as air flows past the outside of the heat exchanger, the air becomes warm. Have you heard this one recently, you have a cracked heat exchanger and your furnace has to be replaced, today. He operned up a port and took a mirror to assess if there were any heat exchanger cracks as the plenum is narrow and i have a 110 input90 output btu unit for a house rated at 75 btu. Cracked heat exchanger deciding to repair or replace. The blower fan of the furnace then comes on and sends air around the exchanger, where it picks up the heat from the furnace wall, then continues into the ducts. Dec 23, 2019 in a home heater, the heat exchanger heats up the air that travels through the ventilation system. How to prevent a heat exchanger crack in your furnace. Were you recently told that your furnace heat exchanger is cracked and needs to be replaced. Located in the center of the furnace, it is where fire, gas and heat connect.
Cracked heat exchanger oxygen reading rises while furnace is heating up at time 1. It is important that the heat exchanger is taken care of as hazards can build from a faulty exchanger. The heat exchanger is aptly named it collects air through the ventilation system and exchanges it to heat with the help of the furnace burners. The easiest way i have found to find a crack in the combustion chamber of an oil furnace is to pull the blower, turn the lights out, turn the furnace on, if it has a crack or hole in the combustion chamber i guarantee you will see it. Needless to say, visual heat exchanger analysis provides woefully inadequate answers to these very important questions. Indianapolis hvac cracked heat exchanger diagnosis furnace.
Mar 19, 2007 the crack is open when the heat exchanger metal is at or close to room temperature. The hot combustion gas in the heat exchanger heats up the metal walls. Dec 02, 2015 a furnace depends on the heat exchanger to contain these dangerous fumes and safely conduct them to the chimney while transferring the valuable heat into the home. The your heat exchanger is cracked so your furnace must be. Its like the doctor that finds cancer it might not be good news, but it. The extra air will cause the oxygen reading to change notably. How to prevent a heat exchanger crack in your furnace hydes. 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. Brian schutt december 21, 2011 chances are if youre reading this, youve had a technician out to your home and theyve told you you have a crack or rupture in your heat exchanger. Unless you are one of the top 3% of people who have all the money, replacing the furnace is going to hurt the pocket book if you have not planed for it, but it has to be done. I open up the plenum and show the crack from the top. When a furnace has a cracked heat exchanger, can it be. 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. 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.
Many homeowners utilize propane, fuel oil, or natural gas to power their heating. This trips a safety switch and shuts down the furnace. Can you repair a cracked heat exchanger on a gas furnace. This effect will get worst as the furnace heats up from expansion and the crack gets bigger. Because the metal of the heat exchanger expands and then contracts as it heats and cools, the stress may eventually cause a crack to form on the. Bobs answer to whether or not a cracked heat exchanger can be dangerous is unambiguous. Anyone who has an oil or gas boiler, oil or gas furnace, gas logs. Many companies use infrared light to detect cracks, but a flashlight is sufficient for more noticeable cracks. But the decision to repair or replace a heating unit can be difficult. Gas burns in the burner, and the heat from the flame is passed into a metal coil known as the heat exchanger. Possible deadly cracks missed in furnace inspections.
This is a requirement, is part of the fuel gas codes and is ultimately not negotiable. My concern is the fact that mechanics walk past other potential carbon monoxide poisoning issues to get to heat exchanger inspection. Read our blog to learn what to do if this happens to you. A damaged heat exchanger in a gas furnace is potentially dangerous to a homes occupants and should not be ignored.
For this reason, i want to share with you some of the common symptoms and causes of a cracked heat exchanger in a furnace. Depending on where the crack is, the supply fan creates a positive pressure on the outside of the heat exchanger that can blow air inside the heat exchanger and on to the flame. Signs and symptoms of a cracked gas furnace heat exchanger. There are certain signs to look for to determine if the heat exchanger has been. A crack in your heat exchanger is no trivial matter. It is a set of metal tubes or coils that connects to the burner assembly and ends at the vent or flue pipe. If there is a crack in the heat exchanger, there is the potential for. In order to help you avoid these safety issues, today were going to talk about how a heat exchanger develops cracks and what you can do to prevent or identify the problem before its too late.
The dangers of a cracked heat exchanger help heating. Furnace heatexchanger crack signs your furnace has one. We find some cracked heat exchangers from the pilot lights that are blown out. If you have a heat exchanger crack, you need to replace the heat exchanger or the furnace. A cracked heat exchanger in a gas furnace is a serious safety issue. When the furnace is in an attic or crawlspace, very few contractors will agree to replace the heat exchanger. A well qualified hvac technician will look for a furnace cracked heat exchanger during a maintenance check. The heat exchanger on a furnace is the section that keeps the combustion chamber and the breathing air separate. Dec 03, 2018 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. For homeowners with newermodel furnaces, there may be a more favorable outcome in the event that a crack develops in their heat exchanger. Jan, 2020 a heat exchanger may crack under these circumstances. Through this crack, combustion fumes can escape from the exchanger, and can build up in the room. Cracked heat exchanger issues will affect how your heating system performs.
Dangerous cracked heat exchangers in furnaces carbon monoxide detectors and cracked heat exchangers. The crack is open when the heat exchanger metal is at or close to room temperature. The longer your system operates with a cracked heat exchanger, the worse the cracks will get. Older furnaces can develop major issues, such as a cracked heat exchanger. Gas furnace heat exchanger clogged problem what it looks like and. Air and gas are separated within the heat exchanger to prevent mixing and exposure to harmful combustion byproducts, such as carbon monoxide. As air flows past the outside of the heat exchanger, the air becomes warm. Its the most common cause of excess carbon monoxide in a home. The reason a crack in a heat exchanger is such a cause for concernand reason to think about replacing a furnaceis because it creates a major health hazard.
Mar 11, 20 both of those cause the heat exchanger to heat up and cool down far more often than if the furnace was closer to the proper size for the home or, better yet, was able to use a lower stage or modulate its heat output for smaller loads. Even though your furnace may look and seem fine, dangerous gases could leak into your home and seriously affect, even kill, your family members. Dec 15, 2007 the correct way to find a bad heat exchanger on an oil furnace is to check flue content either co2 or o2 will surfice. The furnaces blower motor forces air over the heat exchanger, causing the air to increase in temperature. Some people choose to live in denial of the seriousness of a cracked heat exchanger. You can just have the heat exchanger replaced, but it is an expensive repair, and a new furnace is often the smarter investment. Hvac businesses in minnesota lock out furnaces when cracked heat exchangers are found. Is the crack deep enough to leach carbon monoxide co. Heat exchangers sometimes crack as the result of years of regular use. Cracked heat exchanger diagnosis for your furnace in indianapolis by. If a heat exchanger becomes cracked, then your heating system will not perform as it should. Ive heard that penetrating oil, such as wd40, will get through the cracks. Heat safety is paramount so have your furnaces inspected immediately for a cracked heat exchanger.
I show how a furnace reacts when there is a crack in the heat exchanger. Signs your heat exchanger may be cracked on your gas furnace. The heat exchanger is a key part of the furnace and is responsible for the actual heating of air. I will start by saying that everything i write here is my own opinion and experience. Theres a lot of good info on there, but some of it is misleading and there are a lot of straw man arguments made. The heat exchanger on a furnace is the section that keeps the combustion chamber and the breathing air separate 3. The cause of cracked heat exchangers avoid this common scam. In fact, he adds, most heat exchangers have a longer warranty than most other parts of the furnaceoften 10 to 25.
Cracks in the heat exchanger are a serious problem and one that should not be ignored both for the safety of your home and for the longevity of your furnace. Dangerous cracked heat exchangers in furnaces fossil fuels and cracked heat exchangers. Its only going to get worse, not betterthe only question is when. A cracked heat exchanger allows air from the furnace blower to interfere with the flame.
Check and record with fan off and then again with fan on any variance equals bad heat exchanger. In most cases, if the heat exchanger is cracked, your hvac company will recommend replacing the entire furnace. If the heat exchanger is compromised by a crack or rust, flue gases and carbon monoxide will leak into the home resulting in illness and possibly death of the occupants. Diagnosis of a heat exchanger crack typically starts with a noheat service call. The service technician has the time, experience, or even reason to suspect the exchanger is cracked. In this article we discuss residential forced warm air furnace heat exchanger life in more detail, explaining the factors that impact the life of the heat exchanger, things you should do to maximize the life of the furnace heat exchanger, and similarly, things you should not do because they are likely to destroy your furnace before its time. If someone informs you that your heat exchanger is cracked, call the. Furnace heat exchanger replacement costs 2020 costimatesfurnace. A heat exchanger may crack under these circumstances. But we also know that if your heat exchanger truly is cracked, you dont have much time to sit around and waita cracked heat exchanger will leak potentially fatal carbon monoxide into your. If you or other family members experience continual recurring headaches or flu like symptoms, this could indicate a cracked heat exchanger. Oct 18, 2017 the heat exchanger is the furnace component that heats air. Dec 19, 2019 furnace efficiency highefficiency furnaces are more complex and more expensive than 80% furnaces.
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. The heat exchanger is a metal container inside the furnace that collects hot combustion gas from the burners. Our recommendation on finding a crack in a heat exchanger will always be to replace the heat exchanger or the furnace it is in because your familys health and safety is far too important to make guesses and assumptions about how dangerous this crack may or may not be. Old control valves can also cause a heat exchanger to crack. Remove it from the furnace, and examine it in the light. Signs your heat exchanger is cracked romaniuk edmonton. There are two camps ive run into regarding cracked heat exchanger diagnosis. I showed me what could be a crack hairline semicircle in one of the indented circles in the metal. If it cracks after the warranty is up, usually at least 20 years, consider replacing the entire furnace. And what did it mean if the camera revealed a crack.
Thanks for watching guy browns youtube channel was. Your heating fuel typically natural gas, oil, or propane, though electric furnaces use electricity to warm the heat exchanger combusts within the heat exchanger, creating heat that warms its surface. Therefore, having a cracked heat exchanger will affect how your heater works. If the heat exchanger is cracked, the oxygen reading will change a lot when the blower turns on. If your furnace is more than 10 years old, the cracks may just be a sign of expected wear and tear. Aug 31, 2015 finding a crack in the heat exchanger. The heat exchanger vents the gasses that are produced from the furnaces flame. In this way, the combustion gas heats the air without the gas having ever to come in contact with it. Often when cracks are present in a heat exchanger, soot from the combustion process will seep through and discolor the metal. A heat exchanger can be replaced without changing the entire furnace, says bob. Some cracks have been known to only open when the unit is fired and the heat exchanger metal is hot. Those who look for it everywhere and those who dismiss it and never look. We want to caution you about the most common cause for a gas furnace to become unsafe.
In a home heater, the heat exchanger heats up the air that travels through the ventilation system. Any verifiable crack requires replacement of the heat exchanger or furnace. A warning about cracked heat exchangers in gas furnace. Next, turn on the blower and see if there is a change in the exchanger. The heat exchanger is a component of a heating system that transfers heat between fluids to either cool or heat up a home or building. This is because air is leaking through the crack in the heat exchanger into the combustion chamber. Combustible gas increases in temperature and collects in the heat exchanger, allowing it to increase the temperature of the air. The combustible gas will become hotter as it accumulates in the exchanger. Once the heating process is finished, the combustion byproducts in the heat exchanger are vented out of the system through a flue to release the gas harmlessly into the air. Look for signs that the metal has been overheated, or symptoms of longterm metal fatigue. 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.
Danger of a furnace with a cracked heat exchanger servicemax. The american gas association has even put this in writing they say any visible crack or hole is reason. The crack allows the release of dangerous carbon monoxide into the air. When a heat exchanger becomes damaged and the combustion fumes and gases mix with the clean air, serious consequences can result. Depending on the furnace design, it might only be possible to examine 10% of the entire heat exchanger. They observe that their furnace is running just fine and. Should i replace my heat exchanger or buy a new furnace.
If you find that your furnace heat exchanger has trouble getting enough heat and power, then you may find that it has developed a crack or hole. A heat exchanger crack is one of the biggest safety issues that your furnace can develop. A cracked heat exchanger allows air from the furnace blower to interfere with the flame causing it to flutter or even roll out. Consequently, maintaining and inspecting your furnace can help prevent costly furnace repairs. In the video above the furnace techs says the oxygen reading could rise as high as. Mar 17, 2012 for a good example of a hazardous heat exchanger, check out the photo below showing a large rust hole in the heat exchanger of this highefficiency furnace that was only ten years old. The furnace heat exchanger is the one of the main components inside the gas furnace and its used to transfer the heat from the gas burner to the warm air thats blown into your home. This is dangerous, as one of the gases produced by the heat exchanger is carbon monoxide, a deadly. If a heating contractor finds a cracked heat exchanger and says the furnace needs to be replaced, theyre not pulling a scam unless theyre just outright lying to you about finding a crack. They can come inspect your furnace and determine if you do indeed have a cracked heat exchanger. How to prevent a heat exchanger crack in your furnace a heat exchanger crack is one of the biggest safety issues that your furnace can develop. We give free second opinions on cracked heat exchangers.
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