3 Tests for Air Conditioner Refrigerant Leaks

3 Tests for an Air Conditioner Freon Leak

Updated on 8/17/2023

On January 1, 2020, the Environmental Protection Agency (EPA) banned the manufacture of Freon (R-22 refrigerant) because it damaged the ozone layer. Since R-22 was used in nearly all cooling devices at the time, the EPA implemented a step-by-step phase-out.

An air conditioner freon leak is a serious issue. Refrigerants are a key component of any cooling system. Without it, your air conditioning system can’t produce cool air. Read on to see how to check for freon leak in home AC.

Why a Freon Leak Matters

A refrigerant leak can make your home less comfortable and increase your energy costs. In significant leaks, exposure to refrigerant can also be a health concern.

What to Do When Your Air Conditioner has Refrigerant Leaks

Your aging air conditioner has frozen up, and your HVAC technician just diagnosed a refrigerant leak in the system. Now what?

At HomeSense, we don’t recommend adding more refrigerant to a system with known leaks, even though homeowners sometimes ask us to add just a pound to help the situation.

Instead, we recommend a leak test to find and repair the ac leak before adding more refrigerant to the system.

The Types of Freon Leak Tests for an Air Conditioner

1. Electronic Leak Detector Test

Most HVAC service technicians keep an electronic leak detector or sniffer in their toolkits. As the name suggests, the HVAC tech runs this tool along the refrigeration components to detect any R22 or R410a outside of the system. Most HVAC technicians will start a leak test by using this device, as it can be more cost effective in finding a leak.

The limitation to an electronic leak detector test is that it can only scan the components it can touch. With an evaporator coil leak, for example, it can be quite difficult to position the electronic leak detector in all places a potential leak might be.

So while this can be the most cost effective leak test, it is also the most prone to inaccuracy.

2. Nitrogen Leak Detector Test and Bubble Test

An AC leak test with nitrogen—the test we typically use at HomeSense—provides clearer leak detection, though at a slightly higher cost.

With this nitrogen leak test procedure, the HVAC technician first removes any remaining freon or Puron and pumps compressed nitrogen into the refrigeration system. The leaks become audible because the nitrogen is held at a higher pressure than the refrigerant can operate under normal conditions. Think of it like pumping air into a bicycle tire — you can hear where the air escapes.

The technician will also watch the gauges for pressure changes. In a system without leaks, pressure remains constant. A system with a leak will show fluctuations.

Also, the technician will many times take the additional step of “bubbling” the system. The technician will mix up soap bubbles, run it along components of the refrigeration system, and look for air bubbles.

3. Dye Testing for a Freon Leak

A dye test for freon or Puron leaks can also be applied. Here, an HVAC technician adds ultraviolet dye to the system, looking for both constant and intermittent leaks. The UV dye mixes with lubricants within the system and finds its way to even the smallest leaks. The technician uses a blue/black light to see the dye as it leaks out.

It’s important to note that not all dyes are recommended by manufacturers and can have negative consequences on the air conditioning system if the dye is not supported.

If you think you may have a freon leak, contact us. We can help identify and address the issue.