Why Is My Air Conditioner Blowing Warm Air (And How Do I Fix It)?


Troubleshoot: Why Is My Air Conditioner Blowing Warm Air?In the summer, the last thing you want is a blast of warm air coming through your vents when you turn on the AC. After all, isn’t it hot enough outside?

Obviously, there’s a problem with your HVAC system if your AC is blowing warm air. There are many possible causes. But, the good news is that you can do a good deal of troubleshooting before calling a professional.

And, in some cases, you can fix the problem yourself! You don’t even need to be handy or use any tools.

We’ll go over the four most common reasons for your central air system to blow warm air instead of cold. We’ll also talk about how to prevent the problem in the first place.

Meanwhile, if you have any questions about the HVAC system in your Boise Metro home or business, or yours is having problems, call Snowflake Air at (208) 205-9078.

Four Reasons Your Air Conditioner Is Blowing Warm Air

Here’s what to check when your air conditioner is blowing warm air instead of cooling:

  1. Thermostat Settings
  2. Clogged Filter
  3. Coolant Leak
  4. Faulty Compressor

Thermostat Settings

You’d be surprised how often what seems like the cause of a seemingly big HVAC problem is as simple as a wrong setting or low battery. Remember, your thermostat controls your AC and heater. If it’s giving bad signals, you won’t get the comfort you want.

What To Do

Make sure your system is set to “Cool,” and “Auto.” If you’re on “Fan Only,” the system circulates air in the house (which is probably warm already) without cooling or heating it.

Next, check your temperature setting: 78 degrees F is the sweet spot for comfort and energy efficiency, but you can go a little lower if you want.

Last, put in a fresh battery. A thermostat may give the wrong signals if it’s low on power.

Clogged Filter

A Dirty Air Filter Can Cause Clogs And Air Flow ProblemsYour air filter is responsible for preventing dust and dirt from getting into the system. But, if that screen gets clogged, then air can’t pass through either. You end up with either weak circulation or warm air when you want cool air.

What’s happening is that your HVAC system is overheating as it works harder and harder with what little air is coming through the ductwork.

That heat prevents the air from cooling down, and you get warm air when you want air conditioning. In some cases, you may also notice your air conditioner turning off and on again over and over every few minutes. 

What To Do

Change the air filter once a month when you’re running the heat or AC. And every three months when they’re not in use. This prevents the screen from getting clogged.

If the cloth screen on the filter is gray or darker when you take it out, it’s been in there too long and is clogged.


Coolant Leak

As you would imagine by the name, the coolant in your central air system is what makes the air in your home colder. As warm air passes through the system, the heat transfers from the air to the coolant. Then, you’re left with much colder air than when it came in.

The cool air goes back out through the ductwork. And the coolant, or refrigerant, transfers the heat to the condenser outside.

But, if there’s a leak in your AC, you have either no refrigerant or very little. This problem can also result in your air conditioner running without actually cooling the air. In either case, the air keeps passing through the system without getting cooled. It comes back out through the vents just as warm — sometimes warmer — as when it went in.

What To Do

You can’t fix a coolant leak yourself, but the sooner you identify the problem, the faster (and hopefully less expensively) you can get it fixed.

Listen for a hissing noise near your outdoor unit, and check for any sweet chemical smells. You won’t see the refrigerant because it’ll be in a gas state when it hits the air.

But, you can listen for the leak or detect its odor. If you notice these, shut off your system and call a tech. If you catch it in time, you may be able to have it repaired instead of paying the full cost of a new air conditioner if the problem’s too severe. 

Faulty Compressor

Regular Service Is The Best Way To Avoid RepairsThe refrigerant is responsible for removing heat from the air, and the compressor is the component that keeps it pressurized so it can absorb and move that heat.

So, if the compressor is faulty or broken, the coolant can’t do its job. The result is warm air when you want cooling.

What To Do

Once again, this problem isn’t one you can fix yourself. And, the worse news is that it’s often an expensive repair. But, there’s always a better chance that you only need a minor, inexpensive fix if you identify the problem quickly and call for air conditioner repair right away. 

Along with hot air when the AC is running, check if your outdoor condenser is vibrating a lot or is much noisier than usual. Another telltale, but not as common, sign is if the circuit in your breaker box that handles the AC keeps tripping. 

Air Conditioner Repair In Eagle, ID

Snowflake Air has a five-star reputation for excellent air conditioner repair in Eagle, ID along with Kuna, Caldwell, and other Boise Metro. You can call us for a tune-up to make sure your air conditioner is ready for the summer workload. Or, if your AC blows warm air or shows any other signs of problems, click below or call us at (208) 205-9078 to schedule an appointment.