The heat exchanger is one of the most important components in an HVAC system as it is responsible for warming the air during cold, winter months. When the heat exchanger fails, it can pose problems for the household as a broken heat exchanger can cause noxious gasses to leak inside the home.
Most HVAC professionals will not recommend replacing a heat exchanger, and will suggest getting a new furnace installed instead. In this guide, we'll present the step-by-step process on how to replace a heat exchanger, but we recommend asking our experienced technicians for advice before you work on your furnace components.
Diagnosing a Faulty Heat Exchanger
#1 Cracked Heat Exchanger
When the heat exchanger is cracked, it can no longer function properly. A cracked heat exchanger is also highly dangerous to use as carbon monoxide, nitrous oxide, and other harmful gasses can escape into the room, leading to poisoning, respiratory problems, and even death from the leaking carbon monoxide.
You would be able to see visible cracks in the heat exchanger, and other symptoms of a cracked heat exchanger include the presence of soot, strange odors coming from the furnace, and water leaking out of the unit. Cracked heat exchangers cannot be repaired, and you will need to replace a heat exchanger when this happens.
#2 Furnace No Longer Heating
The heat exchanger is responsible for redirecting thermal heat from one medium to another. This is how a heating system works - the heat exchanger turns cool air into warm air, and the furnace blows the warmed air into the room.
Whether you have an electric or gas furnace, the heat exchanger is an essential component of the entire furnace. If your furnace is no longer warming up the room, then chances are you have a faulty, broken, or cracked heat exchanger.
#3 Air Conditioner Not Cooling
Air conditioning systems also use heat exchangers in cooling the room. Unlike the furnace heat exchanger, which blows warm air into the room, air conditioners expel the warm air created by the heat exchanger outdoors, lowering the temperature of the air in the room.
When the air conditioner is not cooling, it may indicate a problem with the heat exchanger of your air conditioning unit. The heat exchanger may not be drawing heat out of the air, which leads to the AC unit not blowing cool air into the room.
How to Replace an HVAC Heat Exchanger: A Step-by-step Guide
Caution: Replacing a heat exchanger is often done by professionals, and is not often a recommended solution as carbon monoxide can easily leak inside the home. Ask our HVAC professionals for advice, and consider replacing your entire furnace instead for better safety, and moderate furnace installation rates!
Step 1: Shut Down the Furnace
First, shut down the furnace, block off the fuel and power source, and let the boiler cool down before working. Wear protective gear such as a dust mask, gloves, protective goggles, and more. Have all your tools on hand - you'll need: a screwdriver or a power drill, the heat exchanger replacement, and other tools depending on the furnace model.
Step 2: Open the Boiler
Open the boiler once it has been cooled down. Heat exchangers are typically located in the boiler of each furnace. Remove the screws that secure the housing of the boiler, and take the panels apart piece by piece. It is a good idea to keep track of the connections by taking a photo of the heat exchanger, and labeling the screws.
Step 3: Remove the Heat Exchanger
Unscrew the heat exchanger from its position, and carefully take it out of the furnace. Make sure to take note of each connected tubing to fit the new component later on. A photo reference is ideal for this work, as you can refer back to the photo when replacing the part.
Step 4: Fit the Heat Exchanger Replacement
Fit the new part into the furnace in the exact same way the old heat exchanger fit into the boiler. Connect the tubing, and refer to the photo you took of the old part when connecting the pieces back together. The new component should look just like the old one.
Step 5: Secure the New, Replacement Heat Exchanger
Secure all the connections tightly, making sure that gas cannot escape into the home. Use your screwdriver or power drill to lock the screws back in place, and secure the housing of the boiler as well. Restore the power back onto your furnace, and test out your repairs.
Looking to replace HVAC ducts? Check this guide.
How Much Does it Cost to Replace a Furnace Heat Exchanger?
How much does a heat exchanger replacement cost? The average cost to replace a heat exchanger is around $1,000 to $2,000 for a standard furnace. The cost to replace a secondary heat exchanger, on the other hand, can go as high as $800 per unit.
However, this cost is exclusive of the labor cost to replace the heat exchanger. Some HVAC repair companies offer packages to purchase and replace a new heat exchanger at optimized costs.
Where to Buy a Replacement Heat Exchanger
Ideally, you would want to purchase a new heat exchanger replacement at the official store of the brand of furnace you have. However, this can be challenging to homeowners as stores may only sell the replacement furnace part, and labor rates are often high.
Purchasing through a reputable HVAC repair company is a better option as they have access to a wide range of heat exchangers that are compatible with your unit, and often include repair services with their packages. At Luce, our professional technicians will be glad to assist you in purchasing and replacing your heat exchanger at moderate costs.
Contact us today, and ask us about our purchasing services to make your HVAC repairs stress-free.
