What do I do now that I know that my Heat Exchanger is bad?
What is a Heat Exchanger?
The heat exchanger in a furnace separates the combustion process from your breathing air. It is a combination metal chamber and passageway that starts at the burner assembly and ends approximately where the chimney vent connects to the furnace. Air is heated as it is blown across the hot metal surface of the heat exchanger. The heated air is then distributed through the house to warm the house.
The heat exchanger must have air (and gas ) tight seals to separate the gasses in the flue products inside the heat exchanger from the breathing air passing over the outside surface. This is because the flue gasses can be poisonous - such as deadly carbon monoxide - and contamination of the breathing air by these gasses pose a health risk and can be fatal.
Why do heat exchangers fail?
All heat exchangers fail eventually. This is because of metal fatigue. Metal when heated up expands and when it is cooled off contracts. This constant expansion/contraction cycle is part of the normal furnace heating process. Over time this constant expansion and contraction has the same effect on a heat exchanger that bending a paperclip back and forth has: it breaks. And, when that happens contamination occurs and it is no linger safe.
While heat exchangers are typically manufactured to last between 10 - 20 years, many factors can accelerate the process of heat exchanger failure. These factors usually fall under the categories of poor maintenance, poor initial design and installation, or poor equipment design by the manufacturer. One or a combination of these factors can result in a heat exchanger failing in a few short years.
How do you know when a Heat Exchanger has failed?
A heat exchanger must be visually inspected on a regulator basis. Visual observation of light or water passing through the breach is a positive confirmation of a crack or hole in the heat exchanger.
What tools are needed to determine if a Heat Exchanger is bad?
The old standby method of a mirror and a flashlight has been replaced by high tech infrared video inspection systems and digital draft meter tests.
What about a Carbon Monoxide Test?
A test for carbon monoxide (CO) can be inconclusive. A test for Co reveals whether a furnace is producing CO. A furnace creating CO is a symptom of poor combustion in the furnace. Unlike a car, CO is not always a by-product of the furnace combustion process. Therefore, a heat exchanger can be breached and if the furnace is not producing carbon monoxide the breach will remain undetected.
What are the options if a Heat Exchanger is bad?
There are only two options if a Heat Exchanger is Bad: replace the heat exchanger or replace the furnace. 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 immediately in cold weather. The other factors are energy efficiency and cost of service which can make replacing the furnace a preferrable option even if the furnace is under warranty and available. If a furnace is out of warranty the preferable option is to replace the furnace.
What about a Carbon Monoxide Alarm?
Relaying on a CO Alarm is not an acceptable solution for a bad heat exchanger. This would be as unsafe as driving a car that has a leak in the brake line - you might be able to brake a few times but you wouldn't want to bet your life on it. Further, it is against the mechanical Code, Fire Department regulations, to allow a furnace to operate that has a bad heat exchanger. A representative from any of these organizations would shut the furnace down.
If your heating unit is more than 20 years old, consider an upgrade to a new system. You can save as much as 40% on your fuel bills and enjoy greater comfort and safety.
Call Our Service Department if you have any Questions 215-945-4833