What is the Heat Exchanger and what happens when it fails?
The purpose of a gas furnace is to heat the air in your home by burning natural gas or propane. The flames and hot exhaust created by the burning gas are forced through a large piece of metal, the heat exchanger. As the flame and exhaust gases pass through the heat exchanger it gets very, very hot. Outside of the heat exchanger, the blower motor blows air from your home past the heat exchanger and the air is warmed and returns to the home. As the furnace heats and then cools, when it is off, the heat exchanger expands and contracts. Eventually, the expansion and contraction of normal operation will cause the heat exchanger to crack. The time it takes for the heat exchanger to fail depends on the quality of the furnace and the quality of the installation by the heating and air contractor.
Once a crack occurs, several negative consequences can occur. First, the flame can be pushed backwards, out of the heat exchanger and into the furnace cavity. This condition is called “roll out”. Most furnaces are equipped with a safety sensor that detects roll out and turns off the gas valve stopping the flame. However, if the safety circuit is not maintained properly it may not identify roll out which could cause a fire in the furnace and potentially spread outside the furnace; a very dangerous situation.
A second consequence of a cracked heat exchanger is that the flame will not burn properly. A flame that does not burn properly can create soot and other harmful by-products including carbon monoxide (CO). Carbon monoxide is an odorless, tasteless, invisible gas that reduces the lungs ability to absorb oxygen (O2). Low levels of carbon monoxide can cause headaches, nausea and lethargy. High levels of carbon monoxide will cause death. Standard CO detectors will only alert at pre-set levels for the purpose of immediate evacuation to avoid death. Standard CO detectors are not designed to detect low levels of carbon monoxide poisoning and therefore do not prevent symptoms from low level poisoning.
A third consequence of a cracked heat exchanger is the potential to introduce carbon monoxide into your home. Every furnace has the potential to produce some level of carbon monoxide. When the furnace operates properly, combustion gases pass through the heat exchanger and vent safely out of the house. When a heat exchanger cracks, the venturi effect can bring some amount of exhaust gas into the home. The amount of gas and level of carbon monoxide depends on a number of factors. But, any level of carbon monoxide in your home can cause poisoning.
For safety reasons, it is the standard of the heating and air conditioning industry to disable a furnace that has a clearly determined crack in the heat exchanger. The heat exchanger or the furnace must be replaced before resuming operation. Because of the serious consequences of a cracked heat exchanger, a quality heating and air service contractor will not tell you that your heat exchanger has a “possible” crack, but will prove it to you through one of a number of available techniques. If a service technician has told you that you have a cracked heat exchanger, Climatize Heating & Cooling is ready and able to give you a FREE second opinion with conclusive proof.
Once a crack occurs, several negative consequences can occur. First, the flame can be pushed backwards, out of the heat exchanger and into the furnace cavity. This condition is called “roll out”. Most furnaces are equipped with a safety sensor that detects roll out and turns off the gas valve stopping the flame. However, if the safety circuit is not maintained properly it may not identify roll out which could cause a fire in the furnace and potentially spread outside the furnace; a very dangerous situation.
A second consequence of a cracked heat exchanger is that the flame will not burn properly. A flame that does not burn properly can create soot and other harmful by-products including carbon monoxide (CO). Carbon monoxide is an odorless, tasteless, invisible gas that reduces the lungs ability to absorb oxygen (O2). Low levels of carbon monoxide can cause headaches, nausea and lethargy. High levels of carbon monoxide will cause death. Standard CO detectors will only alert at pre-set levels for the purpose of immediate evacuation to avoid death. Standard CO detectors are not designed to detect low levels of carbon monoxide poisoning and therefore do not prevent symptoms from low level poisoning.
A third consequence of a cracked heat exchanger is the potential to introduce carbon monoxide into your home. Every furnace has the potential to produce some level of carbon monoxide. When the furnace operates properly, combustion gases pass through the heat exchanger and vent safely out of the house. When a heat exchanger cracks, the venturi effect can bring some amount of exhaust gas into the home. The amount of gas and level of carbon monoxide depends on a number of factors. But, any level of carbon monoxide in your home can cause poisoning.
For safety reasons, it is the standard of the heating and air conditioning industry to disable a furnace that has a clearly determined crack in the heat exchanger. The heat exchanger or the furnace must be replaced before resuming operation. Because of the serious consequences of a cracked heat exchanger, a quality heating and air service contractor will not tell you that your heat exchanger has a “possible” crack, but will prove it to you through one of a number of available techniques. If a service technician has told you that you have a cracked heat exchanger, Climatize Heating & Cooling is ready and able to give you a FREE second opinion with conclusive proof.
