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

why is my air conditioner running but not cooling the house

A well-functioning air conditioning runs in cycles that normally last 15 to 20 minutes. Your system will kick on and run until it arrives at the ideal temperature (whatever you set your thermostat to) and afterward kick off for a couple of moments.

But if your air conditioner just can’t bring down the temperature to the number you plugged into your thermostat, it’s something that you have to be concerned about.  This will increase your electricity cost and put unnecessary strain on your system. 

Before reaching out to your local technician, let’s review some of the reasons why your central air conditioner may be running without cooling down your home. 


A refrigerant leak or low 

Your system needs a refrigerant to cool your space. A refrigerant is the blood of your AC, and, similar to our blood, it for the most part doesn’t get spent, just goes all around. So, in case you are low on refrigerant, it implies you’ve gotten a hole and need to get it fixed.

If there is a refrigerant leak, it suggests that there might be not enough of this liquid required to soak up the warmth within the air. It will cause freezing problems throughout the unit, which might ultimately harm your compressor. When this happens, your air-conditioning system will constantly run, and work harder to cool your home, but won’t be sustainable for long.  This small problem could get costly if not fixed right away. 

Since refrigerant is dangerous to handle, it is advisable to schedule an inspection with your local HVAC technician. 


Air Filtration Problem 

If your AC system is running all the time without actually cooling, the first thing that you must do is check the air cleaner.

Your AC works by drawing in air, cooling it, and distributing it around your home. A clogged AC filter reduces airflow in your system because it can’t get enough air to cool your home properly. It is important to change or clean your air filter regularly to ensure the maximum performance of your system. 

When it comes to air filters, it is important to choose the right one for your system. There are many air filters available in the market. It is possible that your current air filter’s MERV rating is too high or low. 

MERV stands for Minimum Efficiency Reporting Value. It’s a rating scale that goes from 1-16 and may match your HVAC system.

Check to see what air filter MERV works best with your home’s AC. 


Closed or blocked vents

A well-functioning unit must have the amount of air being pulled into its system matches the volume of air being blown out of the vents. A closed or blocked vents limits the amount of air that is coming out. This increases the amount of pressure in your air ducts, which can cause small leaks in the ductwork that could worsen over time. So make sure to check if your vents are wide open. 


Your AC is undersized

A small AC in a big room may be the reason why it’s not cooling especially during those hot summer months. The size of the AC must go with the size of the room. 

If you’ve just had an AC installed in a single room and later increase your living space by adding an extension, you will need to upgrade your AC to cover a bigger space. 


Defective compressor

The compressor, as the core of your AC system, circulates the refrigerant that eliminates the heat from your room’s air and dumps it outside. If it is damaged, then the AC can cool your air. 

A defective compressor is most likely to be replaced since they are airtightly sealed, which means you can’t open them to repair. Unfortunately, the compressor is the most expensive part of the AC. If you’re no longer covered with a unit warranty, it’s better to invest in a new unit. 


Condenser outside unit is dirty 

A condenser is an outdoor unit that removes the absorbed heat from your home. If it gets clogged, it can’t properly expel the heat. Thus, forcing the hot temperature to go back inside the system, raising your electric bills as well as the temperature in your room. 

In order to fix this, you must clean the condenser fins with a garden hose. Remove any clog or debris. Avoid using strong steam to prevent damaging the condenser fins that work to cool the refrigerant. 


Leaky Air Ducts 

After the AC has cooled, the air disperses around your home or room through air ducts in your walls and ceilings. If these are not tightly sealed, the cool air is leaking outside your living space. 

Before totally cooling the air, conditioned air travels through a series of ductwork, reaching the corners of your home. Eventually, air ducts become loosely sealed. This causes cool air to leak and escape, making the temperature in your room higher than expected. 

Duck leaks in your home can be hard to detect since they are mostly hidden in the attic. Here are the signs that you have leaky ducts: 

Higher-than-normal electric bills

You have corners or space that don’t cool well 

Unusual dust in your home (from the dust in your attic)

If you have leaky ducts, you may contact a professional to seal your ducts with metal tape or mastic sealant. 


Leaks in your home 

Similar to leaky air ducts, your home might have holes, ill-fitting doors, and windows, poorly installed vents, and electric outlets that can let the hot temperature in. If there’s much of this heat coming in, your AC won’t be able to cool very well. 


De-rating of AC with age 

Appliances are subjected to aging too. Over time, the efficiency of most appliances falls down. Old air conditioners take more time and electricity to give the usual amount of cooling. 


Direct sunlight on air conditioner outdoor unit

People tend to overlook that the outdoor installation of the AC has a direct effect on the unit’s capacity to function at its optimal level.  If the outdoor unit or the outer part of the AC is directly facing the sun, the efficiency of the air conditioner lessens and it also causes the compressor to stop working completely. Along with lower efficiency comes a high consumption of electricity. 

One of the main functions of the AC is to absorb the heat from inside the room and toss it outside. But if the outside temperature is very high due to direct sun exposure or seasonal humidity, the system won’t be able to deliver the desired temperature. All air conditioners are designed to work at a certain level of temperature and beyond that, they will stop working. 


The thermostat is switched to ON 

Your blower will run constantly if your thermostat is set to ON, even when your system is not cooling. This will result in the warm air blowing from your vents. 

In order for the air to blow on your vents only when the AC is cooling, switch your thermostat to AUTO. 


Circuit breaker fail

Most ACs have two circuit breakers: one for the outside unit and one for the inside. If the outside unit’s breaker has failed, the indoor unit keeps blowing warm air inside your home. 

In order to fix this, you must check the breaker box to make sure that the outside unit breaker is ON. If not, switch it ON. If it trips again, it’s better to call a professional to fix in case there is a bigger electrical issue. Do not attempt to reset it over and over. 


Dirty evaporator coils 

Evaporator coils absorb heat from the air in your room and help to cool the temperature. If the coils are dirty, they cannot function properly until it’s cleaned. 

You can use a mild detergent and warm water to clean the evaporator coil.  But a licensed HVAC technician with professional equipment is best consulted in some cases. 


Power issues

Make sure that your AC is plugged into the outlet properly and that the power cord is still intact. If the outlet and cord are working well, there could be a problem with your electrical panel. 

Air conditioners require a large amount of power to run. If your home might have tripped a breaker, blown a fuse, or have overloaded switches built-in, these could affect the system’s performance. 

The old adage “an ounce of prevention is worth a pound of cure” is true when it comes to your air-conditioning system as well. By having a professional technician perform annual inspections, you can help to avoid any potential AC disruption.