How to Check for Freon In Home AC (Leaks & Level)

Summer is just around the corner, and staying cool is a priority for many. But this time of year, it is just as important to keep an eye on the appliances we rely on to keep us cool.

One of the most common problems homeowners face is poorly performing air con units. Whether they are simply not getting cool enough or making annoying noises, an AC not functioning correctly is frustrating.

If your AC isn’t working as efficiently as you are used to, it could be a sign of low freon levels or a freon leak.

What Is Air Conditioner Freon?

Freon is a non-combustible gas that is used in air conditioners to produce cold air. This refrigerant is arguably the most essential part of any AC unit.

Now, freon is not like gas being used up in a cooker. The only way your central AC will run out of freon is when there is a leak somewhere.

Freon is gradually being phased out of use in home appliances in the US. As of January 2020, it will no longer be possible to buy or import units that use freon. If you’re looking for a more efficient AC, you may be interested in this article.

Still, if you have an older unit, you may be relying on this refrigerant to keep you cool.

5 Signs That AC Needs Freon Recharge

Low levels or leaking freon won’t be able to cool your home efficiently. This is why yearly maintenance is recommended for home AC units.

However, there are easy ways to tell that your AC is leaking or has low freon levels.

  1. The AC unit is not cooling your home.
    One of the first things homeowners notice is that the air conditioner simply isn’t performing as it once used to.Your AC absorbs heat indoors and then dumps it outside. When freon levels are low or leaking, it can’t absorb the heat, so it runs all day without cooling your home.
  2. Increased energy bills
    ACs that run all day but don’t cool your home are not only inefficient, they also cost a lot of money. Spikes in energy bills could be a sign that there is a problem.
  3. Warm air coming from AC vents
    Without a refrigerant or freon, your AC won’t be able to absorb the hot air in your home, which can lead to it circulating the hot air back inside. Warm air coming out of your AC vent is a sign that there isn’t enough refrigerant.
  4. Reduced airflow
    AC units without enough freon can freeze and produce ice. The ice inside the AC blocks airflow, which can cause less air to come from your unit.
  5. Ice build-up and hissing noise
    A noticeable build-up of ice or a hissing sound coming from your air-con unit can be a giveaway sign. Most AC leaks are small, so they can often go unnoticed. But a large leak can cause a hissing noise when you turn it on.

Steps on How to Check for Freon in Home AC

If your AC is playing up, there are a few tell-tale signs that could indicate a problem with your freon.

  1. .Check for Frost Buildup
    Frost build-up can accumulate in the motor and coils when there is a freon leak in your AC unit. This may not always be noticeable, so you might have to get up close and personal with your unit to check thoroughly.
  2. .Hissing sound
    Leaks can cause a hissing or bubbling sound when your air-con is on. Try listening to the refrigerant lines for the hissing sound.
  3. .Soap solution
    One of the cheapest ways to find out if freon levels are low is to do the soap solution test. Mix liquid soap and water together and apply it to the area of the suspected leak. Bubbles will appear as freon escapes which will enable you to identify the leaking area.
  4. .Electronic detectors
    Electronic detectors, sometimes referred to as sniffers, can be purchased to detect freon leaks. They work by emitting a low sound and show a visual indicator if a leak is found.

After following these steps and discovering that freon levels are low, arrange for a professional to charge your AC unit. Low freon levels will not only make your home uncomfortable, but they can also permanently damage your AC unit.


Freon Alternatives: Other Types of Refrigerants

  • R-134A, also known as Tetrafluoroethane (CF3CH2F), has thermodynamic properties similar to R-12 but with insignificant ozone depletion potential and a lower 100-year global warming potential. It is the replacement for R12 and R22 and is commonly used in refrigeration and chillers.
  • R-407C is a mixed refrigerant composed of three ingredients: R-32, R-125, and R-134a. It was developed as a substitute refrigerant for R-22 and is commonly used in air-conditioners and chillers.
  • R-404A has an ozone depletion level of 0, just like R-407C and R-134A. It is commonly used in commercial and industrial transport industries because of its wide temperature range.
  • R-410A is commonly used as a refrigerant in air conditioning applications. It has a better performance compared to R-22 and is less harmful to the Ozone. R-410A or Puron is gradually replacing Freon in home air conditioning units.

People Also Ask (FAQ)

 Is freon toxic?

Freon is a dangerous substance. Inhaling freon produces a high that is similar to drinking alcohol. However, inhaling freon can also cause damage to your vital organs.

How long does freon last in an air conditioning unit?

Forever. The only way you would need to top up freon is when there is a leak in your AC unit. Freon is circulated through the copper lines in the AC unit, so if there are no leaks, it should stay there forever.

Is it bad to run AC with low freon?

Your AC will still be able to function on low freon even though it loses its cooling power. However, low freon levels can damage the compressor, leading to overheating and a more extensive repair bill.

Where can you buy freon air conditioners?

As of January 2020, Freon will no longer be made in or imported to the United States. The good news is, there are a lot of better alternatives available in places such as Amazon or Walmart.

How often does home AC need freon refill/recharge?

Providing everything is working correctly, your air con unit should never need to be refilled or recharged. The only time this may be necessary is if there is a leak.

How do you check freon levels in RV/Car AC?

We always advise calling in a professional, especially when dealing with potentially harmful gases. If you have the right equipment at home, you can follow this video to check your freon levels. Alternatively, you can replace your freon ac unit with one of these modern devices built for RVs.


An air conditioner only works smoothly if all the components are in sync. In the best-case scenario, your AC will never need to be recharged or need more freon.

However, leaks can happen, and it will need your attention before it leads to a high repair bill or your whole unit being replaced. This is why regular air conditioning maintenance should be conducted.

Not only will it ensure that your unit is working correctly, but it will also save you from a very uncomfortable summer and expensive repair bill.

Josh Mitchell

Josh Mitchell

My name is Josh and I am obsessed with DIY and improving my family home. HVAC topics can be tricky for homeowners so I decided to share my knowledge on the subject. When I am not working on DIY projects, you can find me at the beach or my local coffee shop.