HVAC Troubleshooting

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AC Refrigerant Leak Detection and Repair

AC refrigerant is the lifeblood of your air conditioning system. During the refrigeration cycle, the refrigerant moves through the system, changing form from a liquid to a gas as it transfers heat. A refrigerant leak is a major disruption to this cycle.

What are some signs of a possible air conditioner refrigerant leak?

The signs of a refrigerant leak can also be signs of other problems with your air conditioning system, so it’s best to contact your local Trane dealer if you’re experiencing any of the following.

AC not blowing cold air
Increased humidity even when the AC is on
Uneven cooling
Higher electric bills with no rate increase or increased energy consumption

What are some tips for detecting refrigerant leaks?

The best way to determine if your AC is leaking refrigerant is to contact your local HVAC company. HVAC technicians have special refrigerant leak detection equipment, and the skills needed to identify the source of the leak. They can then determine if they can repair the AC leak or if system replacement might be in your future.

However, if you want to do a little investigating yourself, here are some DIY ways to tell if you have a refrigerant leak.

1. Make a visual inspection

Look closely at the fittings, valves, and around the indoor and outdoor unit for any signs of refrigerant leaks, such as an oil stain or oily residue.

2. Listen and smell for leaks

If you hear a hissing sound near the refrigerant lines, you likely have a refrigerant leak. In addition, some refrigerants, such as R-22 (Freon®), can emit a faint, slightly sweet odor like nail polish remover. If you notice either of these, call for AC repair.

3. Apply soapy water to the area of the suspected leak

Fill a spray bottle with water and a little dish soap and shake it. Spray the soapy mixture on the refrigerant lines. If you have a large leak, bubbles will form. However, no bubbles do not mean you don’t have a leak. Smaller leaks are difficult to detect with this method. Consult with an HVAC professional for accurate leak detection.

What causes an AC refrigerant leak?

Several things can cause a refrigerant leak, including:

Wear and tear
Corrosion
Physical damage
Frozen evaporator coil
Improper installation

A trained HVAC technician can help diagnose a refrigerant leak and tell you what caused it.

Can I still run the unit if I have an air conditioner refrigerant leak?

No. Running the air conditioner when you have a refrigerant leak can do further damage to the system as well as the environment. If you or an HVAC technician determines that your AC unit is leaking refrigerant, shut the system off until repairs can be made and the system gets an AC refrigerant recharge.

Schedule AC Repair

Should I pay for air conditioner leak repair or replace the unit?

This is a personal decision based on the age of your system and your financial situation. If you have been spending more and more on air conditioning repairs and your air conditioner is more than 15 years old, replacing it may be a more cost-effective option than repairing it. See our Repair or Replace Guide for some tips on making the decision.

And remember that many Trane dealers offer special 0% HVAC financing.

Ask about a portable AC unit while you wait

If your AC system can’t be revived, but it will be a day or two before your HVAC company can install a new unit, ask if the HVAC company has access to any portable AC units you can use to help keep you cool while you wait.

Anne Fonda, Content Writer at Trane Technologies

A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.

She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism. When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.

Expert review by Kimberly Sexton, Senior Systems Engineer