If you’re sitting in your home on a hot day, enjoying the cool air flowing from your air conditioner, and all of a sudden the air starts blowing hot—it’s a confusing and frustrating feeling. You rely on your AC to keep you cool, so when it starts blowing hot air, it can feel like a personal attack.
Before you start panicking or call for AC repair, it’s important to understand that there are a few reasons why this could be happening. In this blog, we’ll go over five of the most common reasons your air conditioner might be blowing hot air, as well as what you can do to fix the problem.
1. The Thermostat Is Set to “On” Rather Than “Auto”
If your air conditioner is set to “On,” it will blow air constantly—even if that air isn’t cool. This is because the AC unit is designed to cool your home by blowing air over cold coils. However, if those coils aren’t cold, the air that blows over them will also be warm.
To fix this problem, simply switch your thermostat from “On” to “Auto.” This will cause the air conditioner to only run when it’s necessary, rather than blowing air constantly.
2. The Air Filter Is Dirty
Your air conditioner has to work harder to cool your home if the air filter is dirty. This is because the air filter is responsible for trapping dirt, dust, and other airborne particles. If the filter is full of these particles, it will restrict the airflow to your AC unit. As a result, your AC unit will have to work harder to cool your home, which can cause the coils to freeze and the air to blow warm.
To fix this problem, simply replace the air filter. Depending on the type of air conditioner you have, you might need to replace the filter every one to three months.
3. The Evaporator Coils Are Frozen
One of the most common reasons your air conditioner is blowing hot air is because the evaporator coils are frozen. This usually happens when the air filter is dirty or when the airflow to the unit is restricted. As a result, the coils can’t absorb enough heat, causing them to freeze.
If you suspect that the evaporator coils are frozen, turn off the air conditioner and check the coils. If they’re covered in ice, simply thaw them out and replace the air filter. If the coils aren’t frozen, move on to the next potential problem.
4. The Condenser Coils Are Dirty
The condenser coils are responsible for releasing heat from the refrigerant. If the coils are dirty, they can’t release heat effectively, causing the refrigerant to overheat. As a result, the air conditioner will blow hot air.
To fix this problem, simply clean the coils with a brush or a vacuum. You can find instructions for how to do this in your AC unit’s owner’s manual.
5. The Refrigerant Is Leaking
If the refrigerant is leaking, it can’t effectively cool the air. This is a serious problem that should be fixed by a professional.
If you suspect that the refrigerant is leaking, turn off the air conditioner and contact a professional for AC repair.
These are just a few of the most common reasons your air conditioner might be blowing hot air. If you’re still having trouble, contact a professional for AC repair.
