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Why is my air conditioner running but not cooling the house?

When an air conditioner does not cool it can be due to multiple reasons, not simply due to a lack of gas. Most people think of this as the first option, but it is not the only option and certainly the majority of the time it is not the most accurate diagnosis.

Consider that if the air conditioning installation was done properly, the gas should not be lost unless a leak has occurred. For this reason, most of the time your air conditioner not cooling the environment or not cooling enough is due to other factors.

In the following article, we will state several reasons why your air conditioner may not be cooling. Keep in mind that once you identify the reason that fits your case you should take proper action immediately.

Control or thermostat incorrectly configured

Although it may seem silly, there are many people that get confused when turning on their air conditioning system because they do not know how to set the operating mode correctly.

A high percentage of the time, most air conditioning problems are simply due to an incorrect remote control setting. If for any reason you cannot configure your remote or wall controller, it is best to reset it to the factory settings. Once done, you can continue with the tips that we show you below.

First, for cold air conditioning, you must ensure that you have cold mode selected. This is typically a snowflake symbol. It is easy to get confused with the dehumidifying mode, which is typically a drop of water symbol.

Once configured, you need to be patient. This is because in most cases an air conditioner unit may take up to 10 minutes to work once you turn it on with the controller.

Haven’t used the equipment in a while

When you turn on your air conditioner for the first time after not using it for a long period of time, it takes a while for the compressor to start working so that the environment starts to get cold. It usually takes between 3 to 10 minutes, but sometimes even longer depending on the brand and age of the system.

What happens to many people is that when they realize that the aircon is not cooling, they start to touch different buttons thinking that there is something incorrectly configured. The only thing you get with this is the delay remains paused until you stop touching the buttons.

For this reason, you have to put on cool mode, adjust the temperature and ventilation or fan speed, and wait for 3 to 6 minutes. Do not despair and be patient.

If after waiting several minutes without touching anything, with the remote set correctly, it still doesn’t work, then it is better to contact a technician so he/she can see what is happening.

woman hand turning on air conditioning


Problem with the start or run capacitor

When one of the start or run capacitors does not work, either for the fan or the compressor, you will see that the indoor unit is working correctly but is not cooling at all.

When a fan capacitor is deficient, it does not pass on power to the fan motor and the outdoor fan will not work. In this case, it is most likely that a fan-run capacitor is damaged.

On the other hand, when the compressor capacitor is not working, you will see the outdoor fan working correctly but the compressor will be stopped. In this case, it is most likely that the compressor start capacitor is faulty.

In these cases, you need to call an expert to solve the problem. Capacitors can hold their charge long after the air conditioner unit is turned off.  This poses a serious risk of electrical harm if you try to remove or replace any parts on your own.

Dirty air filters

When air filters are dirty, there is a drop in pressure in the indoor unit because the air does not circulate as it should. As a result, you may notice that the equipment cools, and even freezes at the indoor coil, but does not cool down the room.

This will result in higher energy consumption. Even high-powered equipment may stop due to the pressure switch tripping. The AC pressure switch is a safety feature for the aircon for when the pressure is too low or too high.

To clean the air conditioner filters you can simply do it with your hands and a little soap. You can also use a soft cell brush and hot water to make them cleaner and more disinfected. Also, try to perform regular maintenance on your aircon.

Gas leak

Lack of gas may be due to a leak in the refrigeration circuit. This could be either because of an error in the installation or because a small hole has occurred in a pipe due to vibrations, corrosion, or physical damage.

A leak may also have developed within an AC unit itself. Indoor and outdoor coils are the most common internal leak locations, and may be covered by manufacturers’ warranty if the air conditioner is less than 5 years old.

To solve this problem, you will have to call a specialized technician to detect the gas leak.  They can guide you as to whether it is an installation fault, AC unit fault, or simply due to wear and tear.

Outdoor or indoor fan not working

This can be due to various factors. For example, the condenser may be in poor condition, preventing the fan from moving or allowing movement with difficulty. Alternatively, one of the fan blades may have broken, which affects proper functioning of the aircon equipment.

In this case, it is also extremely important to call an HVAC technician so he can check what is exactly happening with the fan. DIY in this area can lead to further damage to the air conditioner or yourself.

Extremely high temperature outside

Air conditioners need to transfer heat from the circulating refrigerant to work properly. When the outside temperature is too high, adequate cooling may struggle to occur.

It may feel like your air conditioner unit is not cooling the indoor space if the ambient temperature is extreme. In this case, the drop in temperature from outdoor to indoor is not sufficient to create a comfortable indoor climate.

A temperature difference of around 10 degrees is considered normal. So, if it’s 30 degrees outside, you could achieve air being blown out of the indoor AC unit at 20 degrees. This is with a fully functioning air conditioning system.

However, if its 40 degrees outside, the aircon would struggle to pump out air below 30 degrees indoors. The system would be pushed to its limits, it would take longer to cool the indoor area, and the degree of cooling experienced may be limited as a result.

Further issues arise when the outdoor AC unit is placed in some type of metal drawer, wooden box, storage area, or any other scenario where ventilation is not good. This reduces airflow, heat rejection, and the subsequent cooling capability of the air conditioner.

To solve this problem, you have to lower your expectations of an air conditioning system on extremely hot days and/or move the outdoor unit to a better place or at least clear obstructions around it.

stressed woman drying sweat using wipe


Useful tips for when we see that our air conditioning does not cool well

The first thing you should do is review all the previous points and identify what your problem could be. After that, if you need help you can contact us to check your aircon system. Otherwise, if it can be solved by yourself, keep in mind that you can give us a call or leave us a comment so we can assess and potentially assist you in the process.

Also, please be aware that you should never manipulate any unit without having HVAC technical knowledge as you could sustain damage in an accident. Apart from further damaging the air conditioning system, you could harm yourself or those around you. Surely it’s worth playing it safe. If needed, we are here to help.