Why Is My HVAC Not Cooling?

Why is my HVAC not cooling?
Sacramento summers can be exceptionally hot, and if you don’t have a functional air conditioner, being home can be miserable. When your air conditioner isn’t functioning as it should, you could be running it round the clock, driving up your energy bills, and not feeling any cool air.

Is your air conditioner having trouble cooling your home? If so, it’s likely to happen in the middle of a hot summer day when it’s crucial you have a comfortable home. Fortunately, we’re here to help anyone dealing with their HVAC not cooling and offer some possible causes, some of which you can handle on your own.

Dirty Air Filter

Air conditioners are equipped with an air filter that’s located around the indoor air handler unit. The air filter captures dust, dirt, and dander to prevent it from traveling through the system and into your home or unit, which can damage the components in your air conditioner. Plus, it helps eliminatedirt and dust in your home which can trigger allergies or respiratory problems.

Image: a clean and dirty air filter side by side so you can see the difference. If your HVAC is not cooling, a dirty air filter could be the culprit.

When your air filter is dirty, the system can’t run efficiently and cool your home. The airflow becomes blocked, preventing cool air from coming in and the hot air from going out. When the filters are severely dirty or blocked, your system may shut down completely to protect itself.

If you’re noticing that cool air isn’t coming out, despite running your air conditioner regularly, turn it off and check the air filter to make sure it’s clean and in good condition.

Incorrect Thermostat Setting

If you have your air conditioner running and it’s still hot and humid in your home, you should check the thermostat settings. It may seem obvious, but someone could’ve changed the thermostat setting inadvertently and created a problem with cool air.

Check the settings to make sure your air conditioner is set to “cool” and check that the temperature is low. You should also make sure the thermostat isn’t on heat or fan, which may be “on,” and switch it back to cool.

Once the system comes back on, wait and see if there’s cool air coming out. If you have some refreshing, chilly air, you know that the thermostat was the problem and how to correct it in the future. If this doesn’t work, you may need to investigate bigger issues.

Condenser Coils Are Clogged

Most central air conditioners have an outdoor condenser unit with a large condenser coil that wraps around most of it. The condenser fan transfers the heat from your home through the coil, which is how it cools.

Image; An HVAC technician cleaning the condenser coils.
The coil has fins along it that are close together, which can build dirt and debris from the outdoors. Over time, this can clog the condenser coil and create a blockage. If your air conditioner is struggling to cool your home, always check the condenser coil to make sure it’s clear of debris.

If it’s clogged, cool air can’t get into your home and hot air can’t be pulled out. In addition, this can reduce your system’s efficiency. You can very carefully clear it yourself with a vacuum and a brush attachment, but we recommend calling an HVAC professional to clean and tune-up your air conditioner.

Refrigerant Leak

Air conditioners have refrigerant to flow through the indoor and outdoor coils. This refrigerant changes from a liquid to a gaseous form to pull heat and humidity from your home and transfer it outside.

Image: an HVAC technician measures refrigerant levels.
When refrigerant leaks, the system has to work harder and still may not cool your house down. If the leak is severe, you may have an air conditioner that’s running all day and night and blowing warm air, failing to remove humidity or cool your home down. If this continues, your compressor can get damaged, or the system may shut down for protection. You should always have a suspected refrigerant leak checked by a professional HVAC contractor.

Air Conditioner Is Too Small

Most people aren’t aware that air conditioners are measured in BTUs, or British Thermal Units. These are the standard units for air conditioners and help you determine the best sized air conditioner for your home or space, taking factors like the climate and your home’s insulation into account. If the system isn’t sized appropriately, it can’t run efficiently and cool your home as it should.

With a system that’s too small, you may notice high energy bills, an air conditioner that runs around the clock, and few results. This may not be obvious when the weather is mild, but it’s likely to become a problem when the heat of summer hits. Though there’s some cost involved, it’s best to replace an undersized air conditioner to enjoy a cool, comfortable home and save on energy bills, which can add up.

Iamge: two condensers, one large one small, to show the difference between a large and small condenser.
Looking for air conditioner repairs or maintenance to tackle the summer heat? Contact Bell Brothers HVAC to schedule an appointment!