Introduction – Gas Furnace Heat Exchanger
A heat exchanger is a device inside a gas furnace used to transfer heat from one medium to another. In a home furnace, a heat exchanger is a metal chamber that uses hot air from the burner to heat the air being circulated throughout the home. The heat exchanger warms the air and pushes it out of the furnace and into the home’s vents. Heat exchangers are important components of a home furnace, as they are used to heat air that is then circulated throughout the home. Without a heat exchanger, a home furnace would not be able to warm the air that is pushed through the home’s vents.
Two Types Of Heat Exchangers
There are two types of heat exchangers commonly used in home furnaces: sealed combustion and open combustion. Sealed combustion heat exchangers are designed with a sealed combustion chamber that prevents combustion gases from entering the home. Open combustion heat exchangers are designed with an open combustion chamber that allows combustion gases to enter the home.
Sealed combustion heat exchangers are more efficient than open combustion heat exchangers, as they do not allow combustion gases to enter the home. Open combustion heat exchangers are less efficient, as they do allow combustion gases to enter the home. The type of heat exchanger used in a home furnace will depend on the particular model of furnace.
A sealed combustion heat exchanger is safer than an open combustion heat exchanger. Sealed combustion heat exchangers are designed with a sealed combustion chamber that prevents combustion gases from entering the home. This design ensures that no hazardous gases are being released into the home, making it a much safer option than an open combustion heat exchanger. Open combustion heat exchangers are designed with an open combustion chamber that allows combustion gases to enter the home, making them much less safe than sealed combustion heat exchangers.
What Is The Heat Exchanger And How It Works In A Furnace
You will want to know what is a heat exchanger in a furnace. We will follow the diagram above with numbered components.
A forced air furnace works by using a series of components to heat up air and distribute it throughout a home. The process begins with 1) the gas intake, which is where the gas supply is connected to the furnace. From there, the gas travels to 2) the burners, which are responsible for igniting the gas and creating heat. The burners cause exhaust to build up which are sent out through a connected 3) exhaust pipe. The heat is contained inside 4) the heat exchanger, which transfers the heat from inside the tubes of the heat exchanger to the air surrounding it. Note the air inside the heat exchanger and the air outside the heat exchanger are not supposed to mix. This heated air is then pushed out of the furnace by 5) the blower fan which draws air from 6) the cold air intake. The 7) heated air finally exits into the home.
How Long Do Heat Exchangers Last
Heat exchangers are made from solid metal and should last anywhere from 10 to 20 years, depending on the particular model and how well it is maintained. They are certainly stressed by the high temperatures of containing the fire of the furnace. In general, heat exchangers will last longer if they are properly maintained and serviced on a regular basis. Preventative maintenance will extend the life of a heat exchanger and ensure that it is working as efficiently as possible. It is important to keep an eye on the age of a heat exchanger and have it inspected by a professional if it is believed to be nearing the end of its life.
Bad Heat Exchanger: Diagnosis And Symptoms
If the heat exchanger is cracked, it can cause the furnace to become dangerous and potentially hazardous to the occupants of the home. A cracked heat exchanger can lead to the release of dangerous combustion gases, such as carbon monoxide, into the home, which can be fatal if not addressed. Additionally, a cracked heat exchanger can reduce the efficiency of the furnace, leading to higher energy bills and reduced performance. It is important to have a professional inspect the heat exchanger if it is believed to be cracked in order to ensure that the furnace is safe and functioning properly.
A faulty heat exchanger can present a variety of symptoms that indicate a need for repair or replacement.
Defective Heat Exchanger Due To Metal Corrosion
One common symptom of a faulty heat exchanger is metal corrosion. Typically, this corrosion will occur in the form of rust or discoloration of the metal, indicating that the heat exchanger has been exposed to moisture and is corroding.
Blocked Heat Exchanger Due To Soot Accumulation
Another symptom of a faulty heat exchanger is soot accumulation. Soot is a byproduct of combustion and can accumulate on the heat exchanger, reducing its efficiency and potentially leading to a fire hazard.
Cracked Heat Exchanger
Finally, cracking of the heat exchanger is another symptom of a faulty heat exchanger. Cracking of the heat exchanger can be caused by age, improper installation, or extreme temperatures and can indicate the need for repair or replacement.
Causes Of A Faulty Heat Exchanger
There are several potential causes of a faulty heat exchanger. One potential cause is the age of the heat exchanger. Over time, heat exchangers can begin to corrode and weaken, leading to cracks and other damage. Another potential cause of a faulty heat exchanger is improper installation. If the heat exchanger is not properly installed, it can be exposed to excess heat or cold and can become damaged. Finally, soot accumulation is another potential cause of a faulty heat exchanger. Soot is a byproduct of combustion and can accumulate on the heat exchanger, reducing its efficiency and potentially leading to a fire hazard.
Get A Professional Diagnosis For Repair Services
Professional diagnosis of a faulty heat exchanger is necessary in order to determine the cause of the issue and determine what repairs or replacements may be necessary. One way to diagnose a faulty heat exchanger is through carbon monoxide testing. Carbon monoxide is a deadly gas that is produced by combustion and can be present in the home if a heat exchanger is faulty.
Carbon monoxide testing can detect the presence of this gas and can help to identify a faulty heat exchanger. Additionally, a professional can perform a visual inspection of the heat exchanger in order to identify any signs of corrosion, cracking, or other damage. This inspection can help to identify the cause of the faulty heat exchanger and determine what repairs or replacements may be necessary.
How To Tell If Heat Exchanger Is Cracked – Blower Fan Method
In addition to the above carbon monoxide test and the visual inspection, here is one final method of checking that there is a crack in the heat exchanger without turning on the furnace. Following our diagram above, you will see that if there is a crack, then the blower will push air into the exchanger, which is not supposed to happen.
You can then detect that air is inside the heat exchanger with a flame test at the burner ports. Therefore the way to do this is to turn on the blower fan without turning on the furnace, and checking for any air coming out of the burner ports.
Summary
In conclusion, heat exchangers are an important component of a home furnace and can be prone to damage and malfunction. There are several potential causes of a faulty heat exchanger, including age, improper installation, and soot accumulation. Professional diagnosis of a faulty heat exchanger is necessary in order to determine the cause of the issue and determine what repairs or replacements may be necessary. Carbon monoxide testing and visual inspections can both be used to identify a faulty heat exchanger. Safety precautions should be taken when dealing with a faulty heat exchanger, and preventative maintenance can be used to help extend the life of the heat exchanger and reduce the risk of malfunction.
