Is your air conditioner not cooling like it used to? As summer approaches, a properly functioning AC system becomes essential for comfort. One common issue that can affect cooling performance is a refrigerant leak.
If your AC unit has ice forming on the evaporator coils, isn't cooling effectively, makes hissing sounds, or emits a sweet smell similar to nail polish remover, these are strong indicators of a refrigerant leak. You might also notice higher electric bills or experience unusual symptoms like sinus pressure when the system runs.
We recommend calling a professional HVAC technician if you suspect a leak. While some homeowners attempt DIY solutions, refrigerant handling requires proper certification and equipment.
A skilled technician can perform pressure tests, use leak detection tools, and safely repair the issue to restore your system's efficiency.
In this guide, we’ll walk you through how to spot the signs of an AC refrigerant leak, what causes it, and what to do if you think your system is leaking.
Here's what you need to know about AC refrigerant leaks:
- Common causes of AC refrigerant leaks and how to prevent them
- How to tell if your AC has a refrigerant leak
- How to confirm and fix a refrigerant leak in your AC
Let's dive in!
Common causes of AC refrigerant leaks and how to prevent them
Refrigerant leaks occur for several reasons, from normal wear and tear to specific component failures. Understanding these causes can help you identify potential issues before they lead to major AC problems.
Where refrigerant leaks usually start in your AC system
Refrigerant leaks typically start at connection points where components join together. These fittings can loosen over time due to temperature changes and vibration. When this happens, tiny gaps form that allow the refrigerant (sometimes called Freon) to escape.
Poor installation is another common culprit. If an AC unit wasn't properly installed, connections might not be tight enough or components might be improperly aligned.
Physical damage can also cause leaks. External impacts, like hitting the unit with lawn equipment, can create punctures in refrigerant lines. Even small dents can eventually develop into leaks.
Corrosion is particularly problematic in coastal areas where salt air can deteriorate copper tubing. This creates pinhole leaks that are hard to detect but can drain your system of refrigerant.
How evaporator coils and copper tubing contribute to leaks
The evaporator coil is especially vulnerable to refrigerant leaks. These coils contain thin copper tubing where the refrigerant absorbs heat from your home's air. Over time, this tubing can develop small cracks or holes.
Formicary corrosion, a microscopic form of damage, affects these coils due to household chemicals in the air. Common products like cleaners and personal care items release compounds that react with copper, creating tiny tunnels in the metal.
The refrigerant lines that connect indoor and outdoor units are also susceptible to damage. These copper tubes run through walls and attics where they might rub against surfaces, creating wear spots that eventually leak.
Factory defects in coils or tubing, while less common, can also lead to premature leaks in newer systems.
How age and wear make refrigerant leaks more likely
Air conditioners aren't designed to last forever. Most units begin showing signs of wear after 10-15 years of operation. The constant pressure changes and temperature fluctuations stress the system's components.
Vibration from the compressor and fan motors gradually loosens connections. What started as a secure fitting when installed can become a leak point years later.
Expansion and contraction cycles weaken metal components over time. As refrigerant pressure changes, tubing expands and contracts slightly, which can create stress fractures.
Regular maintenance helps extend an AC unit's life, but eventually, age-related leaks become inevitable. This is why older air conditioning units typically require more refrigerant top-offs than newer models.
Even in well-installed systems, refrigerant can slowly escape over time. According to the U.S. Environmental Protection Agency (EPA), residential split-system air conditioners typically experience an operational refrigerant leak rate of 1% to 4% per year, not including additional losses from maintenance or improper installation.
This means a system can lose efficiency year after year without showing obvious signs at first.
How to tell if your AC has a refrigerant leak
Refrigerant leaks can cause significant damage to your air conditioning system and lead to expensive repairs. Recognizing the warning signs early can save you money and prevent system failure.
Your AC runs but doesn’t cool? It could be a refrigerant leak
One of the most noticeable signs of a refrigerant leak is when your AC no longer cools your home effectively. Your system may run continuously but struggle to reach the temperature set on your thermostat.
Your vents will blow air that feels warmer than usual. This happens because refrigerant is essential for absorbing heat from your home's air. When refrigerant levels are low due to a leak, the cooling process becomes inefficient.
You might also notice higher electric bills despite not feeling comfortable. Your AC works harder to compensate for the low refrigerant level, consuming more electricity in the process.
Ice formation on the evaporator coils is another indicator. This might seem counterintuitive, but low refrigerant causes the coils to get too cold and freeze up, further reducing cooling capacity.
Hissing or bubbling sounds: a warning sign of refrigerant leaks
Strange noises often point to refrigerant leaks in your AC system. A hissing sound typically indicates a small to medium-sized leak where refrigerant escapes as a gas under pressure.
For larger leaks, you might hear a gurgling or bubbling noise. This occurs when refrigerant escapes from a bigger hole in the system's copper lines or components.
These sounds are most noticeable when your AC is running. Try listening near your indoor unit or along the refrigerant lines that connect to your outdoor unit.
Some leaks are too small to produce audible sounds. In these cases, professional leak detection equipment is necessary to locate the problem.
A leak might be why your AC isn’t controlling humidity
Your AC system does more than cool the air—it also removes humidity. When refrigerant levels drop due to a leak, your system's dehumidification capabilities decline significantly.
You might notice your home feels sticky or muggy even with the air conditioner running. Windows may show more condensation than usual, and the air might feel heavy and uncomfortable.
This increased humidity can lead to other problems, including mold growth, musty odors, and damage to wood furniture or flooring in your home.
The humidity issue becomes especially noticeable during hot, humid weather when your AC should be working hardest to keep your indoor environment comfortable.
Simple humidity tests can confirm this problem. Ideal indoor humidity should be between 30-50%, but with a refrigerant leak, your levels might consistently exceed this range.
How to confirm and fix a refrigerant leak in your AC
Once you suspect a refrigerant leak, you need to confirm its presence and take appropriate action. Proper diagnosis will save you money and prevent further damage to your AC system.
Tools HVAC pros use to detect AC refrigerant leaks
Professional HVAC technicians have specialized tools to accurately detect refrigerant leaks. They typically use electronic leak detectors that can sense even tiny amounts of escaped refrigerant. These devices beep or flash when refrigerant is detected in the air.
Technicians may also perform a pressure test on your system. This involves pressurizing the refrigerant lines and measuring if pressure drops over time. A steady pressure drop indicates a leak somewhere in the system.
Some professionals use UV dye tests. They inject a special dye into your system that circulates with the refrigerant. When checked with a UV light, the dye glows brightly at leak locations, making them easy to spot.
What oil spots and condensation tell you about a refrigerant leak
Oil residue is a tell-tale sign of a refrigerant leak. When refrigerant escapes, it often carries oil from the compressor with it. Look for oily spots on copper lines, connections, or around your air handler.
Excessive condensation or water pooling around your indoor unit can also indicate a leak. This happens because a low refrigerant level causes the evaporator coil to get too cold and freeze over. When the ice melts, it creates unusual amounts of water.
Check the copper lines for frost or ice buildup. With R-410a or other modern refrigerants, freezing on the refrigerant lines means the system isn't operating properly, often due to a leak.
What are your safest repair options for a refrigerant leak?
Never attempt to add refrigerant yourself. Handling refrigerants requires EPA certification and special equipment. Improper handling can be dangerous and is also illegal in many places.
Small leaks in accessible areas might be repairable by soldering or using special sealants. However, leaks in critical components like the evaporator coil often require part replacement.
For older systems using outdated refrigerants, a leak might warrant considering a full system upgrade. Modern HVAC systems are more energy-efficient and use environmentally friendlier refrigerants like R-410a.
After repairs, technicians will vacuum the system to remove air and moisture before recharging with the correct amount of refrigerant. They'll also test the system to ensure proper operation and check that the leak has been fully resolved.
Conclusion
If your air conditioner isn’t cooling like it used to, don’t ignore the signs. A refrigerant leak might start small, but it can lead to higher energy bills, increased humidity, system strain, and even complete breakdown. Catching the problem early protects your comfort and prevents more expensive repairs later.
While it’s tempting to search for DIY solutions, handling refrigerants without proper training is both illegal and dangerous. A licensed HVAC technician can accurately diagnose the leak, repair it safely, and recharge your system with the right amount of refrigerant.
The bottom line? If your AC is blowing warm air, forming ice, or making strange noises, don’t wait. Give us a call to keep your system running efficiently when you need it most.
