On a hot day, there are few things more frustrating than an AC not blowing cold air. Whether the AC is running but not blowing cold air or isn’t even turning on, you know something is wrong.

And that you’re about to have a very uncomfortable day… unless you do something about it.

Let’s take a look at some of the most common reasons why an air conditioner might stop blowing cold air. In many cases, the issue is a simple fix. However, some AC issues could indicate a larger, more complicated repair.

If the air conditioner is running but not blowing cold air…

Let’s say you’ve got the AC set to 75 on a hot June afternoon. You feel air coming out of the air registers, but the air isn’t cold. After a while, you start to notice that you’re not feeling so cool either. You go and check the thermostat. The temperature is rising – it’s already at 79 – but the AC isn’t bringing it down to your setting of 75. What gives?

Any time the air conditioner is not blowing cold air but is still running, you could have one of two different problems:

1. Dirty air filter: If you haven’t replaced or cleaned your air filter in a very long time, the system might be starved for air. A dirty air filter can prevent the AC from cooling properly. Go ahead and replace your filter or clean it according to the manufacturer’s instructions. This might solve the problem!

2. Dirty indoor or outdoor coil: When either your condenser coil (outdoor) or evaporator coil (indoor) are dirty, the air conditioner can’t move heat around the way it’s supposed to. Until you call in a pro to clean the coils, the system is unlikely to cool your home sufficiently.

3. Refrigerant leak: This is a bigger problem than numbers one and two above. If you know your filter is new and your coils are relatively clean, there’s a chance that refrigerant is leaking from your system. The best fix for a refrigerant leak depends on the age of the system and the type of refrigerant it has.

A refrigerant leak is what you don’t want to be the reason for an AC not blowing cold air. Usually, we find refrigerant leaks in the system’s evaporator coil. If your system uses R-410A refrigerant and is still under warranty, the best option is to replace the evaporator coil with a new one. If the system is no longer under warranty or uses the old R-22 refrigerant, you should probably replace the system completely.

Can you top off the refrigerant for the AC to make it through the summer? Maybe. But at this point, you’re basically kicking the can down the road. Refrigerant will continue to leak out of the system and you will have to keep topping it off all the time. For this reason, it’s usually more cost effective to replace the system as soon as you realize there is a leak.

Is your AC not blowing cold air… or any air at all?

This situation might actually seem scarier than when the air conditioner is running but isn’t blowing cold air! Maybe your AC just won’t turn on at all. What should you do?

Well, there’s actually some good news here. Most of the time, an AC that won’t run isn’t a sign of anything particularly serious. Yes, you will probably need service from an HVAC company. No, the problem usually isn’t as severe as a refrigerant leak.

Here are a few reasons you may find yourself in this situation:

1. Dead thermostat batteries: Is the thermostat showing a blank screen? Replace the batteries and see if it turns on! You might not need HVAC service after all. If you replace the batteries and still see a blank screen, there may be a wiring issue. You might also need to replace the thermostat itself.

2. Bad contactor: This is an AC component that can prevent power from getting to the unit if it goes bad. You will need to call a pro to identify the bad contactor and replace it. For HVAC companies, this is a very routine repair.

3. Bad capacitor: Capacitors look like large batteries. They live inside your AC’s outdoor unit and enable the system to start up and keep running. They’re also guaranteed to fail over time. As with bad contactors, replacing a bad capacitor is a very routine task for an HVAC technician.

4. Triggered float switch: If the indoor unit has a water leak or you have a clog in your drain line, the accumulation of water might set off your system’s float switch. A triggered float switch will shut down the unit until you can clear out the water and find out why it was accumulating. You will need an HVAC technician to examine the system and break any clogs in the drain line.

Occasionally, you might find your house AC not blowing cold air for some other reason

The above problems are the most common reasons an AC stops blowing cold air or stops running completely. That being said, your situation could be unique and different! An experienced HVAC technician can troubleshoot the problem and identify the best possible solution.

If you have an AC not blowing cold air and live in the Metro Atlanta region, PV Heating, Cooling & Plumbing can help! Give us a call at (404) 798-9672 today or complete the form below to get in touch!

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