8 Warning Signs Your Air Conditioner Needs Repairs

Does your air conditioner run the way it used to? Sometimes it can be difficult to put your finger on if it’s performing differently. What changed and when did it change?

These can be subtle at first. You may notice a change in airflow from some of your registers. Maybe your AC is running longer or not as long as it normally does. You may even notice new sounds, smells, and pools of water around your furnace.

These signs can indicate that your air conditioner needs service or repairs.

At Fire & Ice, we’ve worked on thousands of HVAC systems, and while we could list the performance benchmarks that we look for as HVAC professionals, that list likely wouldn’t help many homeowners. After all, HVAC service technicians have a variety of tools that can help them diagnose an issue with your air conditioner.

So instead, this article focuses on the changes that you might notice yourself. Air conditioners generally don’t have intermittent issues. When something goes awry, you, as a homeowner, will see/hear it, and the problem won’t start and stop.

And if you find and fix a small problem, you may have saved yourself a repair bill that’s in the thousands rather than in the hundreds of dollars. You may even keep your system from breaking down completely.

In this article, we discuss eight of the most common changes in your air conditioner’s performance that you may notice. We also discuss some of the issues that cause these changes.

1. It Takes a Lot Longer to Cool

The change will probably be subtle at first. It may not even be obvious until there’s a hot spell when the outside temperature lingers above 90 degrees for days at a time. But you’ll have a flash of insight one day when the AC runs and runs and runs.

In this case, a longer runtime can benefit you partially because your air conditioner is removing humidity when it’s running. But a longer run time is a warning sign.

Some of the issues that cause long runtimes include:

Dirt buildup on the heat exchanger. Over time, the heat exchanger can accumulate dirt, soot, and other debris. In Columbus, Westerville, and Worthington, we see this a lot with the cottonwood seeds. This means that your air conditioner has to work harder and run longer to cool your home. Your HVAC technician can address this by cleaning your heat exchanger.

But if it’s more than dirty…

You might have a cracked or malfunctioning heat exchanger. When your system has to work harder (whether because of dirt buildup or dirty filters), parts begin to break down. For heat exchangers, this can mean cracks, corrosion, or other issues. Cracked heat exchangers can lead to complete system breakdowns.

Heat exchangers can cost thousands of dollars to replace once they sustain damage. Fortunately, many furnace manufacturers offer lifetime warranties on their furnaces’ heat exchangers.

Without a warranty, heat exchangers can cost as much as $3,500 to replace. That’s almost as much as a brand new unit.

2. Your Electricity Bills Are Higher Than Normal

If your furnace is losing efficiency, it could be due to many factors. Dirty filter, failing parts, a hole in the ductwork, parts that need lubrication, etc. Sometimes the only clue you have that your air conditioner needs attention is an electric bill. A comparison from month to month, or maybe year to year, can at least give you a sign.

A sudden spike - as long as you know it’s not caused by something else - is a sign of trouble.

3. Your AC is Making Strange Noises

A host of things gone sour can be responsible for strange noises: the compressor, the contactor, the blower motor, etc. Perhaps the most obvious one is a clogged filter by the furnace that’s rattling. A hole in the ductwork might yield a whistling sound. Anything beyond that mandates a call to an HVAC technician.

4. It Feels Muggy in the House

Air conditioning doesn’t just cool the house by removing hot air. It also removes humidity. And if there’s a problem, the indoor humidity might creep up past comfortable levels. If you have a thermostat that can track the indoor relative humidity, keep an eye on it. If the level creeps up, you know you have a problem.

For a small investment, you can purchase a hygrometer, which measures humidity. It can verify that the air is indeed heavier.

5. There’s an Ice Buildup on the AC

Ice can form on your air conditioner if the refrigerant falls below freezing, or it could be caused by faulty wiring or a dirty coil. This will cause poor performance and can even cause a complete failure. Scraping or chiseling ice from your unit could exacerbate the problem. It needs to defrost, and then the problem causing the ice needs to be addressed by a professional.

6. Water Is Pooling Around the Furnace

If you notice water near your furnace during the summer, the seal on your evaporator coil could be compromised. Your evaporator coil is the indoor component of your air conditioner or heat pump. In some HVAC setups, the evaporator coil is located on top of your furnace cabinet.

Your evaporator coil produces moisture – that’s why your air conditioner/heat pump has a drain. But if your evaporator coil isn’t properly sealed, this moisture could leak onto and around your furnace.

You might even notice condensation collecting on the outside of the ducts.

The most common reason for water under your furnace is a clogged condensation drain. Your HVAC partner should be able to do an evaluation and ensure that your furnace isn’t damaged.

7. Unusual Smells Are Coming From Vents

Dirty Sock Syndrome is caused by the buildup of mold and bacteria on your air conditioner. Specifically, this buildup occurs in the system’s evaporator coil, which is housed in the indoor AC unit.

Most indoor air conditioner units are located in a home’s basement. Basements are typically cool, damp, and dark. These are the perfect conditions for mold and bacteria growth. While an air conditioner is designed to handle moisture, the internal components, like anything else in the home, can become dirty and accrue dirt and other particles.

For mold and bacteria to accumulate, they need two things: organic material, and moisture. The dust and dirt that exist throughout any home, and the particulates collected by HVAC air filters, provide plenty of organic materials (most house dust is made of dead skin cells). The other part of the equation, moisture, can be found in most homes, particularly during the most humid times of the year. The result is buildup and smell.

This can be handled professionally or by the homeowner. The drain pan can become plugged up or sometimes starts collecting dirt that can lead to bacteria or mold. Ensuring that it’s clean is a good precautionary measure.

8. There Are Blocked Vents

This could be due to a major collection of dust/mold. Or you might have a nest of some sort. It is not uncommon for ducts to become disconnected or damaged. Pieces of an air filter may have gotten dislodged and wound up in the ducts. An inspection of the ducts can sort that out, and a duct cleaning may be in order.

Besides a loss of comfort, a blocked vent leads to increased static pressure, which strains the entire unit.

What You Can Do Before Your AC Needs Repair

The very first thing you should do is check your filter. A dirty filter can cause noises, can cause very poor performance from your furnace, air conditioner, and heat pump, and can get so clogged that it’s no longer effective. Cheap filters should be changed at least once every three months. More expensive ones can last for the life of the furnace as long as they get vacuumed at least once or twice a year.

You should have regular maintenance. We recommend that an HVAC contractor visit your home once in the fall (to deal with the furnace), and once in the spring (air conditioner or heat pump). A timely visit can catch a problem - such as a refrigerant leak - before it becomes major.

Assessing Your Air Conditioner Repair Options

While items such as regularly changing your filter and checking your drain pan are good advice for any system, if you’re dealing with unwanted odors or you’re being drowned out by a new noise, it’s time to schedule a visit from a repair specialist.

Skipping this could mean a loss of comfort, a higher electric bill, or even the failure of your system.

Having a conversation with a licensed HVAC partner, while also ensuring that everything is clean and running smoothly, is the best first step.

Ready to schedule your in-home service? If you’re in Columbus, OH, or the surrounding area, reach out to us today. You shouldn’t have to go another day with unwanted odors, and we’d love to discuss your options and help you make the best decision for your home.

And if you want to learn more about air conditioners, we recommend reading the following:

Cost of an New Air Conditioner

The Definitive List of Air Conditioning Myths

HVAC Buyer’s Guide