It can be quite frustrating when you run your air conditioner, but it doesn’t cool your house. Not only is it inconvenient, but it can also lead to expensive energy bills. There are several main reasons why your air conditioner is not cooling your home.
Check your filter if your air conditioner is not cooling your house, and replace it if it’s clogged. Refrigerant leaks and frozen evaporator coils can also explain why your air conditioner is not cooling your home. It could also be because your vents or air ducts are blocked. Otherwise, this may indicate that your thermostat is defective.
Most of these fixes are quite simple, but it’s best to enlist the help of HVAC professionals. Follow along as we explore the top reasons why your air conditioner is not cooling.
Why Is My Air Conditioner Running But Not Cooling the House?
Between clogged air filters and faulty thermostats, many things can explain why your air conditioner is not cooling your house. This doesn’t always call for expensive repairs, and many fixes are simple and cheap. Let’s look at the most common reasons why your air conditioner isn’t cooling your house and highlight the best fixes.
1. Your Filter is Clogged
Air conditioner filters protect the unit from dust and debris that circulate throughout your house. The filter catches this debris so it doesn’t damage the unit and make a mess inside your home. However, there is a limit to how much debris filters can catch.
In most cases, air filters become dirty after 90 days, and you must replace them. Air struggles to pass through filters that are clogged and dirty. This can strain your air conditioner and weaken the airflow throughout your house.
Many people assume their air conditioner is broken, but in reality, their filter is just clogged. Ideally, you should always keep extra filters on hand so you can replace them when they become too dirty.
2. Faulty Compressor
Without a working compressor, your air conditioner can’t properly distribute refrigerant. You will experience poor airflow throughout the house. What little air comes from your vents may even be warm if your compressor stops working.
An HVAC technician can fix this problem if they replace your compressor. This is a common repair for air conditioners that are under 10-15 years old. Otherwise, you may simply want to invest in a new air conditioner if it’s too old.
3. Dirty Air Ducts
Just like an air filter, your HVAC system’s ductwork can also get clogged. The dust and debris that clogs your filter can also clog your air ducts. When this happens, the debris restricts the airflow throughout the ducts.
Your air conditioner may work just fine, but you won’t feel it cooling your house if the ducts are clogged. This is an easy fix, and an HVAC technician can simply clean your air ducts. The best option is to clean your air ducts once every 3 to 5 years so they don’t get clogged.
4. You Have a Refrigerant Leak
Refrigerant is one of the most important parts of an air conditioner. It absorbs heat as it transitions from a gas to a liquid, and that’s largely how your AC cools the house. When it becomes low or leaks, the refrigerant cannot undergo this process, and it won’t cool your home.
You can tell this is the case if your air conditioner isn’t cooling the house but your energy bills are high. This can also cause your evaporator coils to freeze. You should never try to fix a refrigerant leak without the help of an HVAC technician as it can be difficult.
5. Your Air Conditioner is Over 15 Years Old
Air conditioners can last up to 15 to 20 years. However, you must repair your air conditioner more and more once it reaches 10 years old. Instead of servicing it once yearly, HVAC technicians will likely have to visit your home more often.
If your AC is 10-15 years old and requires a repair that costs more than $5,000, get a new unit instead. Old air conditioners simply can’t keep up with your home’s cooling demands, and they require expensive repairs.
6. Your Vents Are Blocked
Is the airflow strong in some parts of your but not in others? If so, that could be because some of your vents are blocked. That can explain why your air conditioner is not cooling your house, and it’s an easy fix.
Simply check each of your vents to make sure they are open. It’s easy to accidentally block vents with decorations, furniture, and clutter in your home. Uncover the vents, wait a few minutes, and see if your house cools off.
7. Improper Thermostat Settings
Did you set your thermostat to “fan on”? If so, that could explain why your air conditioner is not cooling your home. It may cool your home when the AC is running. However, the fan won’t cool your home if it stays on when the AC isn’t running.
This is a common mistake. Many people assume that running the fan means it will keep cooling your house. It may improve the airflow and feel pleasant, but not all of the air that comes out will be cool. You may even feel warm air in some cases.
You can only guarantee that the fan will keep cooling your house if the AC is cycling. That doesn’t mean you must turn the fan off, but you must realize it’s not the same as cycling the AC.
8. Obstructed Outdoor Condenser
Your air conditioner’s outdoor condenser unit is essential for cooling your house. Because it’s outside, it’s easy for the unit to get obstructed by debris and even plants. Condenser blockages are common in fall when leaves and other plant matter fall onto the unit.
It can also become blocked in spring and summer when mold and mildew conditions are most common. Luckily, HVAC professionals can easily fix this by cleaning the condenser unit.
9. Your Thermostat is Broken
If your air conditioner is not cooling the house, it may be because your thermostat is broken. This can also happen if your thermostat is low on batteries or the batteries are dead. A faulty or broken thermostat cannot send signals to your air conditioner.
It could be as simple as rewiring or recalibrating your thermostat. However, you may need to replace your thermostat altogether, and it’s worth the cost. This may even lower your energy bills as faulty thermostats mess up the AC cycles which can be expensive.
10. Frozen Evaporator Coils
Evaporator coils are essential to cooling your home. They effectively remove heat from the air with the help of your HVAC system’s refrigerant. Unfortunately, evaporator coils can freeze due to clogged drain lines, dirty air filters, and even mold and mildew.
Once this happens, they can no longer remove heat from the air. Your air conditioner won’t be effective at cooling your home, and this can lead to other problems. For example, your AC’s drain pan may become too full, and it can become moldy.
In that case, your house may smell musty whenever your AC runs and the fans blow.
Luckily, it’s easy to repair frozen evaporator coils in most cases. Once thawed, a technician must thoroughly clean the coils. That said, you may simply need to replace the evaporator coils if they are beyond repair.
So, How Do I Fix My AC Running but Cooling?
Replace your filter if your air conditioner is running but not cooling. You may also need to have your air ducts cleaned in that case, and that is necessary every 3-5 years.
Have an HVAC technician inspect your evaporator coils, condenser unit, and thermostat if the problem continues. Many people simply need to replace their thermostats or get more refrigerant.
