The refrigerant is a vital component in your air conditioner, as this is what circulates through the system and removes the heat from the air — effectively creating the cold air that blows into your home. If the refrigerant leaks out, your AC unit will no longer cool your home properly.

Cause

Refrigerant should circulate in a closed system, which means it doesn't leak out, get used up, or typically require refilling. Leaks can occur, though. The most common culprit is a failed seal on the refrigerant pipes that allows it to leak out. 

Older air conditioner units are more likely to spring a leak from issues with corrosion. Over time, the moist environment around an AC unit can cause lines or fitting to develop small amounts of corrosion. This corrosion can lead to pinholes that are just large enough to allow refrigerant to escape. You may not even lose all of the refrigerant at once, as this can be slow process that gradually leads to a decline in cooling power. 

Symptoms

If the leak is in progress, such as a slow leak from a pinhole in the line, then you may hear a hissing or bubbling noise as the refrigerant escapes. This will be most noticeable near the AC unit when it is not running. You may not find any actual leaked fluid, though, as most refrigerants quickly evaporate.

Another clear sign of low refrigerant is when the unit seems to run correctly, but it only blows out lukewarm or hot air. Without sufficient refrigerant, the AC simply can't produce cold air anymore. The AC may also pop on more frequently since it isn't able to properly cool to the desired thermostat settings. 

Solutions

The solution to the problem depends on the age of your air conditioner. Older units may use refrigerants that are no longer allowed due to environmental concerns. It isn't possible to recharge these units, so a replacement with an AC that uses modern refrigerants is a must.

For a newer unit, your AC tech will find the source of the leak. Once the lines or seals are replaced, they will then recharge the unit with new refrigerant and bring it back up to the pressure so it works efficiently. Tests will then be performed to ensure that the leak has been fixed and that the AC is now working as it should. 

Contact an air conditioner repair and installation service to learn more about your options.