Heat Exchanger Problems

Detect and Repair Heat Exchanger Problems in Your Furnace

The heat exchanger is one of the most vital parts of any oil or gas-powered furnace. Your furnace uses this key component to transfer heat from the combustion chamber to your home’s central heating ducts. So keeping your furnace’s heat exchanger in good working condition is always important.


Regular, professional furnace inspections and maintenance is the best way to prevent heat exchanger problems.

Unfortunately, while heat exchangers are built to last, they do suffer wear and tear over time.

Heat exchanger failure in an aging furnace can occur very suddenly and unexpectedly, and this can cause serious problems with your home’s central heating system. With that in mind, it’s never a bad idea to familiarize yourself with the most common signs of heat exchanger failure.


Does Your Furnace Have a Faulty Heat Exchanger?

If your furnace’s heat exchanger is damaged or doesn’t function correctly, you may notice the following problems.


Flickering Yellow Flames

If you look through the inspection window of a properly functioning oil or gas furnace, the flames you see will almost always be blue or white in color. However, some high-efficiency furnaces may produce a slightly yellow flame. But, in any case, the flames produced by your furnace should be steady and even, with very little visible flickering.

If you look through your inspection window and see flickering yellow or orange flames, your furnace may be suffering from a damaged heat exchanger. This occurs when a cracked heat exchanger allows air to escape from the combustion chamber, which deprives the flames of oxygen and prevents them from burning evenly.


Excess Soot

If a damaged heat exchanger is preventing oxygen from reaching the combustion chamber, your furnace may also start to produce large amounts of soot. These solid deposits collect on the interior surfaces of the furnace, which creates a feedback loop; as more soot accumulates, it blocks off more of the furnace’s air supply, causing even more soot to be produced.

If your furnace’s flue belches out black, sooty flames, this can be a sign of heat exchanger failure. You may also be able to see soot deposits through the combustion chamber inspection window.


Visible Rust and Corrosion

Soot deposits in your furnace’s flue can also prevent smoke and other byproducts from exiting the combustion chamber quickly. Once the furnace is deactivated and the chamber cools down, these byproducts can mix with liquid water from condensation, which creates an extremely acidic and highly corrosive liquid that can severely damage metal components.

The heat exchanger’s proximity to the combustion chamber makes it particularly vulnerable to corrosion. If you see any visible rust on the interior or exterior surfaces of your furnace, you can safely assume that the heat exchanger has been damaged, even if your furnace does not seem to have any other problems.


What Should You Do If the Heat Exchanger Is Faulty?

If you suspect that your furnace has a damaged heat exchanger, deactivate the furnace immediately. If your heat exchanger is cracked or its seals have perished, carbon monoxide and other poisonous gases can be released into your home — a problem with potentially lethal consequences.

Once you have fully deactivated your furnace, call in a professional for a full furnace inspection.

These services can detect any signs of damage to your heat exchanger, and they can even detect microscopic cracks through infrared sensing equipment.

If your furnace’s heat exchanger does turn out to be faulty, you have two options: replace the heat exchanger, or replace the furnace.

If your furnace is relatively new, a heat exchanger replacement may be your best bet, especially if your furnace is still covered under warranty. Make sure that your replacement exchanger also comes with a replacement guarantee.

However, if your furnace is older, replacing the heat exchanger may be impractical and expensive.

Many HVAC specialists might advise you to replace your furnace that is more than a decade old, even if it is functioning well.

If you have any more questions about furnace repair or the importance of regular furnace inspections, contact the HVAC experts at Chrismon Heating & Cooling.