Is Your AC Blowing Hot Air in Car? Here’s What to Try

Here in sunny Arizona, where temperatures can climb to 120°F, the last thing you want is to be driving without air conditioning. At its best, a broken A/C system is uncomfortable. At its worst, it can actually pose a serious risk to your safety. 

To stay cool on the road this summer (and year round), learn what you need to do when your A/C is blowing hot air. 

First Steps to Follow


Sometimes, you’re feeling hot air simply because, while your air conditioning system might be on, you haven’t hit the “cool” setting. After making sure the system is set to cool, double check that you’ve lowered the temperature enough. 


Are you going up hill? 

If you’re driving up a steep hill and notice your air conditioning is blowing hot air, it’s best to turn off the system completely. Many modern vehicles purposely start blowing warm air to conserve power for the engine, and some are even able to tackle the incline without changing the air temperature at all, but if you’re unsure about your car’s capabilities, switch off the A/C!

Is it hot outside? 

The hotter the temperature outdoors, the harder your air conditioning has to work. In extreme temperatures, like those we experience in Arizona, your cooling system is putting itself under extra strain. As a result, it may partially or completely lose its cooling ability.


In some cases, hot air can be a sign of a potentially expensive or dangerous problem. For example, if your engine is overheating because the A/C system was under too much strain, you might see the engine warning light come up on your dashboard or steam billowing out from under the hood. 

On top of the hot air, if there are signs that something serious might be going on, pull over and call a tow truck. After all, it’s better to be safe than sorry. 

Before You Head to the Mechanic, Try These Tips.  

Even when restoring cool air isn’t a quick fix, you typically don’t need to visit a repair shop right away. Here are some common issues that you can fix at home.  


Refrigerant (or “coolant”) is a liquid that removes heat from the cabin of your car as it circulates, and when it’s not at the right level, none of the other parts in your A/C system will work. If you notice the refrigerant level is low, you can typically fill it up on your own. 

When to see a mechanic: While you can refill refrigerant yourself, only a mechanic is able to confirm whether there’s a leak. Refrigerant contains antifreeze, which evaporates when it comes in contact with the atmosphere, meaning a refrigerant leak will be nearly impossible to spot. Mechanics use a special dye that can trace any leaks through the system. 


Some car models include a cabin air filter, which will gradually get dirty and clogged over time. If you notice loud noises and musty odors in addition to hot air when your A/C is running, it’s time to purchase and install a new filter (your car’s manual should have instructions on how to do this). 

When to see a mechanic: Usually, air filter replacements are a simple process that can be done at home, but they can also be replaced as part of a car’s regular tune-up service. 


The condenser is responsible for keeping your refrigerant moving and expelling hot air from your car, so when it breaks, the refrigerant can’t do its job. Sometimes, road debris can block the condenser’s ventilation holes, and fixing your A/C is simply a matter of removing any buildup. 

When to see a mechanic: If the condenser is not blocked and still not functioning properly, you’ll generally need a complete replacement, which can only be done by a trained mechanic. 

Don’t just stay cool this summer. Stay safe. Get the driving skills and tips you need to know this season and year round when you take one of our Stop and Go Driving School courses.