What Are the Signs of a Refrigerant Leak in Your AC?

Refrigerant is the substance your AC uses to absorb heat from inside your home and release it outdoors. It circulates through a sealed system, which means it doesn’t get used up over time. Under normal conditions, it should stay at the same level for the life of the system.

If your AC is low on refrigerant, there’s a reason, and in most cases, that reason is a leak.

Signs That Strongly Point to a Refrigerant Leak

Although HVAC technicians can easily diagnose a refrigerant leak, there are no external visual signs homeowners will typically see. However, there are some HVAC performance issues that are closely tied to refrigerant levels, especially when they show up together.

• AC blowing warm or noticeably warmer air: When refrigerant levels drop, the system can’t absorb and remove heat effectively.
• Hissing or bubbling sounds near the system: These can indicate refrigerant escaping from a small leak or a larger opening in the line.
• System struggling to keep up during normal conditions: The system may underperform, even on relatively mild days.

How an HVAC Technician Diagnoses a Refrigerant Leak

The good news is refrigerant leaks are fairly easy to test for, and the results can clearly eliminate other potential culprits:

• Refrigerant carries a small amount of oil, which can leave behind visible traces at the leak point
• Freezing at the evaporator coil or along the refrigerant line is a common side effect of pressure-related issues tied to low refrigerant
• Refrigerant line pressure readings outside the normal range
• Electronic leak detection or dye testing allows a technician to pinpoint the exact location of the leak

Signs That Could Be a Refrigerant Leak (But Often Aren’t)

These issues can be related to refrigerant problems, but they’re not reliable indicators on their own.

• Higher energy bills: Can also be caused by dirty coils, poor insulation or aging equipment.
• Longer run times: Could also point to airflow issues, thermostat problems or duct leakage.
• Uneven cooling: Often tied to ductwork or airflow balancing rather than refrigerant levels.

Why Refrigerant Leaks Happen

Refrigerant doesn’t disappear on its own. Leaks develop due to physical issues within the system.

• Corrosion in the evaporator coil
• Vibration loosening connections over time
• Factory defects or weak coil materials
• Damage to the refrigerant line set
• Age-related wear in older systems

What a Real Refrigerant Leak Repair Includes

A proper refrigerant leak repair typically involves:

• Finding the exact source of the leak using detection tools or testing
• Repairing or replacing the failed component (coil, line or fitting)
• Pressure testing the system to confirm the leak is resolved
• Evacuating the system to remove air and moisture
• Recharging the system to the correct level based on manufacturer specifications

Simply adding refrigerant without fixing the leak is not a long-term solution. The system will lose refrigerant again, often in a matter of weeks or months.

When Repair May Not Make Sense

Not every refrigerant leak leads to a straightforward repair.

• Evaporator coil leaks can be expensive to fix relative to system age
• Recharging older systems using phased-out refrigerants may be significantly more expensive
• Multiple leaks or widespread corrosion often point to larger system issues

In most of these scenarios, the leak is just the tip of the iceberg and more expensive repairs are soon to follow. These problems are often a sign that a system is past its prime and is likely less efficient and effective than a new HVAC system.

Have Your AC Checked if You’re Seeing These Signs

If your system is freezing up or struggling to cool, it’s worth having the issue properly diagnosed. Refrigerant problems don’t resolve on their own, but they are often fixable for a reasonable price compared to some other AC repairs.

Call Tom’s Mechanical at 817-277-4493 for AC diagnostics and dependable refrigerant leak repairs in Arlington or Fort Worth.