What is the furnace coil, and what are things that can go wrong with it?

Split systems—combination HVAC setups that contain both heating (typically a furnace) and cooling (either an air conditioner or heat pump) components—have something unusual not found in ordinary furnaces: a furnace coil. But, just what is a furnace coil, and how do they work? In this article, we’ll explore this little-understood part and explain why it’s a big part of your split system’s performance—and why keeping it clean matters.

First, a quick note: if you need furnace or heating services here in Chicagoland, you’ll want to call the team here at King Heating, Cooling & Plumbing. Our techs know their way around all kinds of furnace setups and installs, and we can help address your maintenance, repair, and installation needs. We always recommend having us do a seasonal furnace tune-up in the fall to clean the furnace coil and other parts of your system.

What exactly is the furnace coil?

This type of furnace coil is commonly known as an "A Coil" because of its distinctive shape.

This type of furnace coil is commonly known as an “A Coil” because of its distinctive shape.

Commonly known as “evaporator coils” or “A Coils” due to their distinctive triangular shape, furnace coils play an important role in your split system.

Air conditioners and heat pumps both work by moving heat from one location to another. For both systems in the summer, this means taking heat from inside the house and moving it outside. This is accomplished with refrigerant. As the refrigerant moves through the evaporator coil inside your home, it absorbs heat. That refrigerant then travels outside, where the heat is expelled and the refrigerant is then cooled, starting the cycle over again.

Heat pumps, of course, are able to reverse that operation in the winter, pulling heat energy from outdoor air (it might not seem like it on a cold Chicago night, but there’s some ambient heat energy there!) inside and expelling cold air.

Why is the evaporator coil installed with the furnace?

During the winter, as your furnace uses gas or electricity to generate heat energy, the furnace coil acts as a heat exchanger, absorbing that heat so that the blower can distribute it through your air ducts.

Why is cleaning the coil so important?

Furnace coils are not only typically inside the furnace assembly, but may be in their own casing, as well. Most of the problems associated with dirty coils come from the lack of access homeowners have to clean them.

Dust and dirt

The buildup of dust and dirt can cause problems. Dirty furnace coils are not as good at transferring heat energy, and you’ll start to see your system’s energy-efficiency dip. In severe cases, extremely dirty coils can trap heat inside your furnace, causing the system to overheat and trigging temperature failsafes that shut off the system entirely.

Mold and mildew

When the air conditioner or heat pump is in use during the summer, the cold refrigerant stored in the heat exchanger, reacting with the warm air in your house, can cause the exterior to generate liquid condensate. This can lead to ideal conditions (warmth and water) for mold and mildew to develop. For obvious reasons, you’ll want to deal with this before it negatively impacts your indoor air quality.

Cleaning the furnace coil

As previously mentioned, it’s nearly impossible (and certainly not advisable!) for a homeowner to reach the furnace evaporator coil. The best time to get your coils cleaned is during your seasonal heating tune-up, which we recommend scheduling in the fall before the first truly cold days of winter. The earlier you book your tune-up, typically the easier it will be to schedule you in.

To make sure you stay on top of your furnace maintenance on an annual basis and avoid any problems, we recommend joining our maintenance program. Known as the King Royal Treatment Plan, this program includes regularly scheduled tune-ups and a number of other perks. Probably the best part of this plan is that we call you to schedule the service appointment. Nifty, right?

Why can’t I clean my own coils?

Beyond how difficult they are to access, we don’t recommend diving into your own furnace. You run the risk of voiding your manufacturer’s warranty when you open up your own system, and there’s always a chance that something can go wrong or get broken, making our 24/7 emergency repair a necessity. Worst case scenario, if not done right, you run the risk of harming yourself.

Honestly, take it from us: when you don’t have the right tools or the right training, it’s just not worth the trouble. It doesn’t even guarantee that your furnace will run any better!

Replacing the furnace coil

In the event that your furnace coil has stopped functioning altogether, you’ll need to have it replaced. The part you’ll need is dependent on your system’s manufacturer, the model, the system’s orientation, and more. For instance, Carrier—the brand King installs—has several types of coils, both in cases and out-of-cases. We recommend giving our team a call so that a technician can match you to the right part you need for your specific system.

Call King and get help from expert technicians

Our advice? Let our experts handle your furnace repair and maintenance—including cleaning your condenser coil. Contact King today for 24/7 repair.

Signs you have furnace problems in Chicago this winter

We’re in the middle of the winter season here in Chicagoland, and many furnaces are pulling multiple shifts just to keep up with your home’s heating needs. Furnace problems can often come out of nowhere, but knowing the signs of trouble can help you take quick and decisive action to get your furnace fixed—before it breaks down.

When you encounter furnace problems, contact the experts at King. We offer 24/7 furnace repair here in Oak Forest, Joliet, and surrounding areas.

What are the signs you have furnace problems?

There are four prominent signs that your furnace is on the verge of a breakdown. Here’s what you should be on the lookout for:

#1. Your heating bills are constantly increasing

One of the most common and obvious signs your furnace needs repair is that your heating bills are continuously increasing. Poorly maintained furnaces often become less effective and require more energy to run at full capacity. (That’s why a furnace tune-up is so important!)

Be on the lookout for increased utility bills this winter. If your December bills are incredibly high, consider calling our team for a furnace inspection and repair.

#2. You hear strange noises from your furnace

Strange noises coming from the furnace is one of the most prominent red flags when it comes to the health of your furnace and heating system. If you hear screeching, popping, humming, or banging sounds coming from your furnace, you probably have furnace problems.

Call an expert right away and get your system checked before it stops working altogether.

#3. You smell gas or other strange smells

If you have an older furnace in your home, you should have a working carbon monoxide detector and be on the watch for any gas issues.

Older furnaces have a higher chance of developing a cracked heat exchanger—a fault that has the potential to release deadly carbon monoxide gas into your home. Other furnace problems can lead to gas you can smell. Be vigilant, and—when in doubt—call in the experts.

#4. Your furnace isn’t performing to your expectations

You should be able to trust your furnace to keep you and your family warm all winter. If you’re encountering cold spots in your home, a lack of heat at night, or other problems, don’t just settle for poor heating. A heating system that is struggling to keep up with your needs is a heating system in need of repair or replacement.

Furnace problems don’t just go away magically. What’s a minor inconvenience today could turn into a full breakdown during the next blizzard. Call King to schedule a heating tune-up or for repair if you suspect something is wrong.

Call King in to address you furnace problems this winter

These are just some of the warning signs that can help you identify that your furnace is in need of repair or maintenance. Look out for these signs and—if you notice any of these—call the experts at King right away.

For professional furnace repair and maintenance in South Side Chicago, the South Suburbs and Parts of NW Indiana, contact our team.