Why Is My HVAC Not Cooling?
When it’s hot and humid outside, air conditioners are the best thing to keep your home cool and comfortable. If your air conditioner isn’t working properly, you’ll notice that you don’t feel any cool air and you’re sweaty and miserable in your own home.

If your air conditioner is struggling to cool your home, you’re probably noticing the problem in the middle of a hot summer. Just as your furnace breaks in the middle of subzero temperatures, your air conditioner is going to have problems during the hottest days of the year.

Find out the possible causes of an air conditioner that isn’t cooling your home and what you can do to fix it.

Dirty Air Filter

A dirty air filter is a common cause of cooling problems. All air conditioners have a filter that may be located in or around the indoor air handler unit. This is designed to capture dust, dirt, and dander to prevent it from entering your home. You can preserve your indoor air quality, and the components in your system are safe from damage from debris.

Image of a dirty and clean air filter side by side. A dirty air filter could be a reason why your HVAC not cooling.
However, if your air filter is dirty, the system can’t run efficiently. A dirty or overfull air filter blocks airflow and prevents cool air from entering your home. If the blockage is severe, your entire system may shut down as a safety precaution. So, if you have your thermostat set low and you’re not getting any cool air, turn the system off and inspect the air filter to make sure it’s clean.

Incorrect Thermostat Setting

For homes that feel hot and humid, make sure the thermostat is set correctly. Though it may seem simple, having the wrong thermostat setting could be the underlying problem with your air conditioner. Check the thermostat settings to ensure the system is set to “cool.” You should also check that the temperature is as low as you want it, and that the thermostat is on and not set to fan or heat.

When you power the system back on, wait a few minutes and then check if there’s cool air coming out. If it works, you know that the only problem was an incorrect thermostat setting. Otherwise, you may need to consider bigger issues with your system.

Condenser Coils Are Clogged

Central air conditioning often has an outdoor condenser unit that features a big outdoor coil that wraps around it. When the system runs properly, the condenser fan transfers air into the outdoor unit through the coil, which pulls heat from your home.

These tight coil fins can harbor dirt and debris, which can clog the condenser coil. If your home doesn’t feel cool while the air conditioner is running, check that the coil is clean and clear of debris.

When it gets clogged, it reduces the cool air that can go into your home and limits the system’s efficiency. You can try to clear it yourself carefully with a vacuum but be careful not to damage the unit.

Refrigerant Leak

Refrigerant is a chemical that’s essential to cooling. It flows through the indoor and outdoor coils, switching from a liquid to a gas form to draw humidity and heat from your home and transfer it outside.

If you have a refrigerant leak, the system can’t cool your home effectively. With severe leaks, your air conditioner may blow hot air or run constantly without actually cooling your home or removing the humidity.

Over time, this can damage your compressor or cause the system to break down completely. If you think you have a refrigerant leak, make sure to call a professional HVAC contractor to inspect and repair it.

Air Conditioner Is Too Small

You’re probably familiar with BTUs, the measurement for air conditioners. Short for British Thermal Units, BTUs are how you determine that the size of your air conditioner is appropriate for your home and its features, including its insulation and your local climate.

Getting the right sized air conditioner is crucial to having a system that runs efficiently and cools your home as it should. A system that’s too small will have to work even harder to cool, shortening its lifespan without delivering the results you want.

When the weather is mild, you may not notice the inefficiency of an undersized air conditioner. But when the temperatures start to rise, you may find that your unit is struggling to cool your home. In this case, it’s best to replace your unit with one that’s fit for your home. Though it’s an upfront cost, you’ll save on energy bills and get better results with a replacement.

If your air conditioner needs to be repaired or tuned up to keep up with the summer heat, contact the pros at ASI Heating and Air to schedule your appointment!