10 Signs of an Air Con Refrigerant Leak & What to Do Next

Signs that your aicon has a leak

With temperatures rising in Australia, more and more people are having air conditioning units installed at their homes and businesses. This also means more people will require assistance when their air con isn’t working, including refrigerant leaks.

When you hear hissing sounds, see fluid leaking, or notice your air conditioner is very slow to cool, there is a chance that your air conditioner’s refrigerant is leaking. If this is the case, you need to contact a repair technician for proper diagnosis and service.

Refrigerant leaks are dangerous to the environment in your home, and it’s important to repair them quickly. As such, we have created a guide below consisting of the ten most common signs of air conditioner refrigerant leaks, what causes them, and what to do if you think your air con unit might be leaking refrigerant. 

If you are keen to learn about these, read on below.

What is an Air Conditioner Refrigerant Leak?

Air conditioners cool the air through what is known as a refrigerant – a fluid that serves as the primary cooling component of air conditioning units. A refrigerant leak in air conditioners occurs when this liquid or gas seeps out of a damaged air conditioner through holes or cracks.

Holes or openings inside the air conditioning unit where refrigerant leaks out often start small but gradually increase in size, usually due to the high pressure. 

Beyond causing air conditioners to cool less, refrigerant leaks are health and environmental hazards. These chemicals are toxic substances that pose a great risk to anyone who inhales them. In addition, they harm the environment by damaging the atmosphere’s ozone layer.

Although refrigerant leaks are not as common as you think, they still occur frequently enough that air conditioning specialists are always ready to conduct repairs. Remember that refrigerant leaks can also occur in brand-new units, usually when not installed properly. 

Experienced air conditioning repair technicians can test for refrigerant leaks, and this can be one of the things included in AC servicing. Testing for leaks typically involves using Nitrogen because of its low molecular weight.

What are the Most Common Signs of Air Conditioner Refrigerant Leaks?

Although not common knowledge, there are many signs that you can look out for to identify refrigerant leaks in your air conditioner. 

The signs are usually a combination of visible symptoms (such as leaking and bubbling sounds) and observable symptoms (such as weak cooling and airflow and longer cooling cycles). 

Learn all about 10 common signs of air con refrigerant leaks below:

1. Poor Cooling

The refrigerant is the principal component of your air conditioner that cools the air. It absorbs heat from the interior and releases it outside. Low refrigerant levels will consequently result in much poorer cooling capability.

An air conditioner requires a certain amount of refrigerant to effectively and efficiently conduct heat transfer. Low levels of refrigerant significantly reduce or outright prevent heat transfer. 

Although refrigerant leaks do not always cause poor cooling performance, they remain among the most common causes. Small leaks may take some time to exhibit symptoms, but larger leaks will be immediately obvious because they will drastically lower refrigerant levels inside your air conditioner. 

2. Hissing or Bubbling Sounds

Refrigerant comes in either a liquid or gaseous state and circulates through the air conditioning system’s coils with high pressure. This pressure consequently creates a hissing or bubbling sound that is often audible enough whenever the air conditioner is running with a leaking refrigerant. 

Once again, such sounds are not only caused by refrigerant leaks, but they are among the most common causes.

3. Weak Airflow

Check the airflow by putting your hand directly in front of the air conditioner’s vents. If the air coming out is cold, but the airflow is weak, then it may be a sign of a refrigerant leak. Similar to the first sign, low refrigerant levels will greatly reduce the production of cold air. 

Due to the complexity of air conditioners and the number of components that work together, a refrigerant leak is not always the cause of weak airflow. As such, it’s best to check for other signs of refrigerant leaks to confirm that your system actually has a leak.

4. Evaporator Coils Bubbling

Small bubbles, often too small to be seen from a distance, will show up around the holes on the evaporator coils when there is a leak. They are usually referred to as ‘champagne leaks’ by people in the HVAC industry due to their resemblance to champagne.

5. Noticeable Water Leaks

If you’re wondering why your air con is leaking water, low refrigerant is one of the more concerning culprits. Whenever your air conditioner stops running or is turned off, the evaporator coils’ frozen condensation will melt, and water will then drip onto the floor. 

Take note of the evaporator coils; if they weren’t frozen before the air conditioning unit was turned off, yet you see a puddle below the unit, it might indicate a refrigerant leak.

6. Lengthy Cooling Cycles

Refrigerant leaks make it much more difficult for your air conditioner to reach your thermostat’s temperature setting. This, in turn, requires your unit to run longer than usual to arrive at the designated temperature because the refrigerant absorbs the heat from the interior. 

So if you notice that your AC is taking too much time to cool, then it might be time to have it checked by a professional.

7. Frosty or Frozen Evaporator Coils

If your air conditioner is freezing even during the peak of summer, then low refrigerant levels due to leaks are most likely the culprit. With less refrigerant circulating through the evaporator coils, less heat is absorbed, causing the condensation on the coils to freeze up fast, even during hot summer days. 

This is one of the more dangerous signs, as it could cause a system breakdown, leaving you with the need for a costly repair job, which may include having to replace the compressor. So if you notice ice formations on the coils, you might be dealing with a refrigerant leak.

8. Significantly Higher Utility Bills

In relation to the previous signs, air conditioners will have to work harder to reach the desired temperature or adequately cool the interior. The side effect of this is that the air conditioner will consume much more electricity for the same amount of cooling. 

So if you notice that your energy bills have been unusually high despite having no significant change or increase in consumption, a refrigerant leak is a possible cause.

9. No Cool Air

One of the most telling signs of a refrigerant leak is the absence of cold air entirely. Without any refrigerant left or low refrigerant levels, the air conditioner may no longer cool your home correctly, if at all. 

If you notice no change in the temperature even after the air conditioner has been on for a while, this might be the result of a refrigerant leak. Confirm by placing your hand directly across the vents to feel the air. If the air is warm, it is possibly a refrigerant leak.

10. Increased Humidity Indoors

Dehumidifying is part of an air conditioner’s cooling process, and the benefits of dehumidification will be provided by a properly functioning unit as early as 15 minutes after being turned on. 

So if you feel like the interior is still very humid, or if your humidity sensors show unusually high humidity, then calling a technician to check for any leak would be best.

What are the Main Causes of Air Conditioner Refrigerant Leaks?

Of course, refrigerant leaks happen for a reason. While some problems only occur after an air conditioner has been in use for years, refrigerant leaks may occur as soon as the unit is installed and even during its first few years. 

It isn’t wise to rule it out when diagnosing your air conditioning unit, even if it is still relatively new.

 We have listed the primary and most common causes of refrigerant leaks below.

1. General Wear and Tear

As with every machine, simply using the air conditioner will subject it to general wear and tear. Although how fast this happens largely depends on how often and long the air conditioner is in use, the joints and connections inside the air conditioning unit will inevitably weaken and erode. The rubber seals around the service valves and access fittings will also wear out and possibly lead to leaks.

2. Lack of Maintenance

A lack of professional maintenance is another major contributing factor to refrigerant leaks. Again, much like other machines, routine servicing and proper maintenance will be critical in keeping the air conditioner in good condition. 

The frequency of maintenance visits from your technician may vary depending on the model and make of the air conditioning unit so consult your local air conditioning specialist. But the point here is to ensure that your air conditioner is regularly serviced.

3. Physical Damage

Outside of the usual wear and tear, other external factors may cause damage to your air conditioner. The most common culprits are physical damage caused by small children and animals playing near the unit. 

However, the fact that lawnmowers are among the most common causes of physical damage is not common knowledge. Their clipping can fly or shoot into the outer portion of the AC unit and cause debris build-up over time. This can be mitigated or prevented by surrounding the outdoor unit with a block wall or installing it higher up.

4. Corrosion

There are two types of corrosion that occur in air conditioners – bimetallic/galvanic corrosion and formicary corrosion. A refrigerant leak may happen with both, but it more commonly occurs in the latter. 

Formicary corrosion usually occurs due to a user error since it requires three elements: water, oxygen, and an organic acid. In addition, the metals used in the air conditioning unit have to be pure copper for this to occur.

Not all cleaning solutions are harmless to the components inside an air conditioner. It’s best to check the manual or consult with your local air conditioner technician to ensure that the interior components do not get damaged.

5. Poor Installation

As stated in the beginning, refrigerant leaks may also occur in brand-new air conditioners. This happens when the unit is improperly or incorrectly installed. Careful installation is necessary to avoid refrigerant leaks. 

The best way to prevent a leak is to ensure that you only have your AC unit installed by well-known and licensed air con technicians, especially those with good reviews.

Are Air Conditioner Refrigerant Leaks Dangerous?

Yes, although air conditioner refrigerant does not have a taste or smell, it is a hazardous substance that poses a great danger to humans, the environment, and the AC unit itself whenever a leak occurs.

The health hazard posed by refrigerants is serious. People exposed to refrigerants for long periods are afflicted with ‘refrigerant poisoning’. Although accidents of this nature are extremely rare, it is important to be aware of the danger it presents. 

If you suspect a leak after noticing the signs, call a licensed technician immediately. Ensure that only licensed professionals deal with refrigerant leaks and refills and that you do not ignore the warning signs.

Older refrigerants contain Hydrofluorocarbons (HFCs) and Hydrochlorofluorocarbons (HCFCs) – substances that come with their own dangers to the environment, as they are considered to be extremely potent greenhouse gases. For instance, a popular refrigerant HFC 134-a has 3,400 times more global warming potential than one of the most common greenhouse gases, carbon dioxide. 

Although most modern AC units have begun switching to safer R410A refrigerants, many air conditioners still use the older, less environmentally friendly refrigerants. Because many homes have air conditioners that still use these types of refrigerants, it’s vital to contact an air conditioner specialist if you notice any signs of a leak in your system. 

What Should I Do if my Air Conditioner Has a Refrigerant Leak?

In the event of a suspected or confirmed refrigerant leak, turn off the air conditioner immediately and isolate the power. Very small and controllable leaks may sometimes be remedied using sealants or tapes. However, due to the dangers posed by the substance, only a licensed professional should perform the repair.

For larger refrigerant leaks, the only solution is to call a licensed professional to conduct the repairs immediately. As previously stated, exposure to refrigerants puts people in the vicinity at risk, and could cause symptoms such as nausea, breathing difficulties, vomiting, and headaches, among others. 

After a leak has been sealed, it may be necessary to conduct an air conditioner regas – a process that involves removing current/ remaining refrigerant inside the AC unit and replacing it with a fresh supply.

Related Questions

How Much Does it Cost to Fix an Air Conditioner Refrigerant Leak?

The exact cost of an air conditioner refrigerant leak repair depends on several factors such as your location, the type, model, and make of your AC unit, as well as the severity of the leak and if a regas is needed. However, a ballpark figure for 2022 is around $100 to $220 per hour, depending on the type of air conditioning system. 

How Common Are Air Conditioner Refrigerant Leaks?

Air conditioner refrigerant leaks are relatively common. This is partly due to the wide range of things that may cause them, from poorly installed air conditioning units to old and improperly maintained AC units. As such, you should have your air con unit regularly serviced to detect any problems early.  


This article is published in good faith and for general informational purposes only. It does not constitute an estimate or quote for any specific service. Platinum Power & Air does not make any warranties about the ongoing completeness, reliability and accuracy of this information. This article is not intended to replace consultation with a licensed air conditioning technician.

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