Otherwise ill use a mirror or my inspection camera. Many companies use infrared light to detect cracks, but a flashlight is sufficient for more noticeable cracks. The shape of the coils depends on the type or model of your furnace. A furnace with a cracked heat exchanger will definitely produce carbon. The crack is open when the heat exchanger metal is at or close to room temperature. Air and gas are separated within the heat exchanger to prevent mixing and exposure to harmful combustion byproducts, such as carbon monoxide. An oversized furnace can also cause overheating and heat exchanger cracks. The lennox limited warranties are voluntary manufacturers warranties for residential application only and are subject to applicable terms and conditions, which include, but are not limited to the warranty period, component availability, and excluded components, repairs, care of equipment, coverage, exclusions. Does anyone have a compatible heat exchanger to replace. The heat exchanger on a furnace is the section that keeps the combustion chamber and the breathing air separate. Please read this article about why heat exchanger cracks do not allow carbon monoxide into the house. 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. Lennox furnaces are engineered with one of two types of heat exchangers. The first step is simply to look where most homeowners cant.
But the decision to repair or replace a heating unit can be difficult. We have read field reports of heat exchanger cracking and carbon monoxide hazards involving the lennox gepnnnnn series heating furnaces. Heat exchanger can crack for various reasons and should be checked every time furnace is repaired or maintained. Simple furnace heat exchanger test hvac learning solutions. Rapidtech course lennox cracked heat exchanger in 1990, when i started as a service technician, i had the privilege of working on literally thousands of these lennox gas furnaces.
The cause can be improperly adjusted burners or a cracked heat exchanger. Mar 11, 20 meanwhile, your heat exchanger will go through a lot of stress when it is constantly overheated and cooled back down. Jan 23, 2020 my lennox g8q390e9 furnace has worked for 50 years. According to the tech, the heat exchanger is under lifetime warranty and we would have to pay for the blower control board. If the igniter fails or cracks, the furnace wont heat. But, unless something else is wrong with the furnace, the additional carbon monoxide simply goes up the flue with the rest.
In the unique design of this heat exchanger the sides of the clam section. Were you recently told that your furnace heat exchanger is cracked and needs to be replaced. The only problem is the heat exchanger is getting quite brittle. Diagnosis of a heat exchanger crack typically starts with a noheat service call. I sent a short answer, but thought this was deserving of a longer answer in the form of a blog post. When a furnace has a cracked heat exchanger, can it be. Theres a lot of good info on there, but some of it is misleading and there are a lot of straw man arguments made. A cracked heat exchanger allows air from the furnace blower to interfere with the flame causing it to flutter or even roll out. This is an excellent way to get honest input from trained craftsmen.
However, professional hvac technicians always check heat exchangers for damage during their preseason maintenance inspection. It is important that the heat exchanger is taken care of as hazards can build from a faulty exchanger. This video is part of the heating and cooling series of training. Its comprised of a set of tubes or coils that repeatedly loops through the airflow inside the furnace to heat the air.
A clogged air filter restricts airflow through the furnace, overheating the heat exchanger, and eventually resulting in stress cracks. The blower then sends that air into a ventilation system via its fan which then gets sent into your home. Because of this, lennox recommends the use of a carbon monoxide detector in your home, even if you do not own gas appliances. For residents of georgia, having an hvac, or heating, ventilation and air conditioning system, is imperative. A crack in your heat exchanger is no trivial matter. If you see a clamshell shaped petal chamber or a number of them arranged in rows in your furnace system, youve likely identified your heat exchanger.
It is a set of metal tubes or coils that connects to the burner assembly and ends at the vent or flue pipe. If you are a technician this is a must see video on where these lennox curved heat exchangers fail. I will have another company come out to give me a second opinion. Even though your furnace may look and seem fine, dangerous gases could. According to the tech, the heat exchanger is under lifetime warranty and we would have. Cracked heat exchanger on lennox furnace we had a technician come out today to diagnose a problem with our furnace and upon inspection he noticed that there was a crack in the heat exchanger and the blower control board needs replacing the original problem. Some cracks have been known to only open when the unit is fired and the heat exchanger metal is hot. The cause of cracked heat exchangers avoid this common scam. Prevent a cracked furnace heat exchanger romaniuk edmonton. A rusty heat exchanger, or one which has a rust hole or crack may be unsafe and risks leaks of dangerous, even potentially fatal carbon monoxide co flue gas.
Older furnaces can develop major issues, such as a cracked heat exchanger. A cracked heat exchanger in a gas furnace is a serious safety issue. My lennox furnace is eighteen years old and is working well mechanically. I bought a house with an old lennox pulse furnace and am getting conflicting information about it. Lennox furnace heat exchanger cracked and is releasing. Duralok plus heat exchanger, built for lennox highefficiency 90% condensing gas furnaces, thats made of high. Heat exchanger cracks can range in size from small, almost imperceptible fissures, to gaps wider. Jan 21, 2020 your heat exchanger is a component applying heat to the air that your blower uses. Combustion gases leaking from a cracked heat exchanger can cause frequent headaches as well as flulike symptoms. The heat exchanger is the furnace component that heats air. Read our blog to learn what to do if this happens to you.
In many cases, the cost to replace just the furnace is not much more than replacing the heat exchanger itself. Combustion pollutants, such as carbon monoxide, nitrogen dioxide and sulfur dioxide, can cause eye and nose irritation, disorientation, sleepiness and nausea. Heat exchanger assembly, 108k btu, stainless steel. Located in the center of the furnace, it is where fire, gas and heat connect. We had a technician come out today to diagnose a problem with our furnace and upon inspection he noticed that there was a crack in the heat exchanger and the blower control board needs replacing the original problem. Lennox duracurve aluminized steel heat exchanger lennox developed heat exchanger eliminates fatigue failure, ticking, resonance and cleanability problems. Either the heatexchanger or furnace must be replaced your options if the heatexchanger has cracked. Consider a ventilation system if your home includes any of the following. A damaged heat exchanger in a gas furnace is potentially dangerous to a homes occupants and should not be ignored. My lennox g8q390e9 furnace has worked for 50 years. As the air passes through the furnace, the heat exchanger warms the air. Furnace heatexchanger crack signs your furnace has one. 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.
A look at a heat exchanger crack that cant be found youtube. There are only two options if a heat exchanger is bad. 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 exchanger. Apr 20, 2020 run like hell from this lennox furnace. Cracked heat exchanger furnace trouble shooting help.
At this point, the carbon monoxide output of the flame is raised. The long reaction of combustion gas and metal leads to corrosion that weakens the exchanger and allows cracks to form. Owners of lennox furnaces in this series who discover this fact after july 1, 1999 should still have the furnace heat exchanger inspected for safety, regardless of whether a new heat exchanger will be provided under warranty. Although a crack in a heat exchanger is dangerous, it does not necessarily mean that carbon monoxide is escaping into your house. Refer to the lennox equipment limited warranty certificate included with the equipment for details. 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. A warning about cracked heat exchangers in gas furnace. A furnace with undersized ductwork will lack proper airflow and suffer a similar fate as that of a clogged filter. The heat exchanger is a key part of the furnace and is responsible for the actual heating of air. That showed us more of the heat exchanger, but it still didnt show us. Also, that the xair % does not necessarily mean that the heat exchanger is cracked. The author has been in the industry for years as a trainer for hvac technicians. If theres a possibility of your heat exchanger being cracked, dont ignore it. Press this onto the furnace heat exchanger, and allow it to dry.
Corrosion because of reaction between the combustion gas and the metal often because of improper venting can also weaken the metal to the point where cracks. Meanwhile, your heat exchanger will go through a lot of stress when it is constantly overheated and cooled back down. Dec 02, 2015 the most common cause of an overheated heat exchanger is as simple as a dirty air filter. This process enhances your comfort and helps control wintertime condensation. Even hairline cracks open, close, and expand as the heat exchanger heats and cools thousands of times over the course of the winter.
Its the most common cause of excess carbon monoxide in a home. Lack of airflow also leads to much longer heating cycles, so not only is the heat exchanger hotter than it needs to be, it also has to endure the pain for a great time. Heat exchanger, pressure switch, induction fan, water leaks and more, except heat. To the best of my knowledge there is no reason that this should have occurred, other than a basic design flaw in the unit. If someone informs you that your heat exchanger is cracked, call the tedder company, and one of our.
The furnace lennox g26q34 was installed around 1996. Pour a little bit of the chemical on the hole, and leave it to dry until it seals around the exchanger. Should i replace my heat exchanger or buy a new furnace. Often when cracks are present in a heat exchanger, soot from the combustion process will seep through and discolor the metal. Even though your furnace may look and seem fine, dangerous gases could leak into your home and seriously affect, even kill, your family members. How do you guys diagnose cracked or bad heat exchangers. I have noted that the g23 heat exchanger has a 20 year warranty and that it should take around 90 minutes labor cost to replace it.
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. That being said, none of the products of combustion belong in the living space. This trips a safety switch and shuts down the furnace. The service technician has the time, experience, or even reason to suspect the exchanger is cracked. Although we cant completely prevent cracked heat exchangers, there are a few steps you can take to prevent them from cracking.
When i do furnace inspections i do a quick look for cracks everytime. It was better than nothing, but it was still only slightly better than flipping a coin. Gas furnaces whisperheat g20ex engineering data upflow gas. However, the heat exchanger has developed a crack that allows flue gas and carbon monoxide to leak into my home to leak into my home. If the part is under warranty but not available, ask the contractor to call the manufacturer and request the cost of the. The igniter gets very hot and glows bright orange to light the gas burner. If not the heat exchanger is considered leaky and could be unsafe. Dec 16, 2012 heat exchanger can crack for various reasons and should be checked every time furnace is repaired or maintained. Your heat exchanger is a component applying heat to the air that your blower uses. Cracked heat exchanger deciding to repair or replace. Thermal fatigue in hvac heat exchangers hvac investigators. Visually check heat exchanger for cracks you will find most cracks form near the back and where the heat exchanger metal bends, since this is where it will be weakest due manufacturer weakening the metal by bending.
Cracked heat exchanger on lennox furnace the furnace lennox g26q34 was installed around 1996. At its outset, a cracked heat exchanger is a problem that will go unnoticed by most homeowners. So on the lennox duracurve heat exchanger its on the bottom curve in the back. Ive got a new born baby in the house and this junk of a furnace is always down. In this video you will discover where all the lennox curved heat exchangers fail and why. Most cracks will be where there is a curve in the metal. If the heat exchanger is under warranty, this is a good way to go. We want to caution you about the most common cause for a gas furnace to become unsafe. 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. Proper diagnosis of a failed or cracked heat exchanger.
A cracked heat exchanger is pretty serious, as far as safety for your home goes. You will find most cracks form near the back and where the heat exchanger metal bends, since this is where it will be weakest due manufacturer weakening the metal by bending it. In hvac heat exchangers, thermal fatigue is accelerated by the corrosive combustion gasses that pass through the heat exchanger tubes on their way to the exhaust flue and by condensation that may collect in the heat exchanger during heat transfer. Danger of a furnace with a cracked heat exchanger servicemax. It is a system which controls the primary climate inside your house or home enabling you to stay comfortable and healthy.
Lennox g 2003 4e 1003 has a crack in the heat exchanger. Do you have a cracked heat exchanger in your furnace. Can you repair a cracked heat exchanger on a gas furnace. Back in the day, the only way to check a heat exchanger for cracks was to perform a visual inspection. Ideal for homes in cooler regions, a healthy climate hrv harnesses heat from inside your home and transfers it to incoming fresh air from outside. A heat exchanger is a heating component inside furnaces that transfers heat to the surrounding air, which is then distributed throughout the home. If you have an iron heat exchanger, then you need to find an iron repair liquid, which uses chemical reactions to seal holes in iron. Signs and symptoms of a cracked gas furnace heat exchanger. Oct 11, 2012 i have noted that the g23 heat exchanger has a 20 year warranty and that it should take around 90 minutes labor cost to replace it. 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. The most common cause of an overheated heat exchanger is as simple as a dirty air filter. Lennox product warranty information lennox residential. Mar 19, 2007 the crack is open when the heat exchanger metal is at or close to room temperature.
To find just the right part, enter your model number. A gas furnaces heat exchanger is the furnace component that actually heats the air. To determine if the igniter is faulty, remove the igniter and. I bought a house with an old lennox pulse furnace and am. The discharge air coming out of the furnace and moving through the duct work will be somewhere between 40 and 90 degrees hotter than the return air. Hvac businesses in minnesota lock out furnaces when cracked heat exchangers are found. The draft inducer motor draws air into the heat exchanger and. Either the heat exchanger or furnace must be replaced your options if the heat exchanger has cracked. Many times, smaller cracks cause the burner flames inside the heat exchanger to waver back and forth and be blown against the inside of the heat exchanger.
217 1596 1248 474 576 1134 1147 1072 1131 965 578 377 729 1357 1115 1354 757 710 177 917 895 735 1130 529 4 1015 1204 1288 778 865 1133 444