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Car’s Air Conditioning ONLY Blowing Hot Air? Here’s Why!

Car’s Air Conditioning ONLY Blowing Hot Air? Here’s Why!

Car Ac Blowing Hot Air

It’s one of those scorching summer days in Ottawa. The weather’s so blazing hot you can barely drag yourself from your air-conditioned house out to the car. But at least the car’s AC will cool you down once you turn it on, right?

Wrong. When you turn on your vehicle’s air conditioning, the vent blows hot air right into your face. So why is your car AC blowing hot air? You’re really hoping you don’t need automotive mechanic services in Ottawa

1. Malfunctioning Electrical System

Your vehicle’s AC is electrically powered, and the most common reason for car air conditioning blowing warm air is an electrical issue. It could be a blown fuse, faulty wiring, or other types of electrical problems. 

If any one of the components in the system’s arrangement of fuses, relays, and switches isn’t working correctly, the entire electrical system will shut down and lead to blowing hot air.

SOLUTION: Due to the electrical system’s complexity, you should have it checked out by a reliable mechanic.

Car air conditioning

2. Low Or Leaking Refrigerant

Refrigerant (also known as “coolant”) is a fluid that cools your passenger cabin as it alternately expands and condenses, circulating throughout the air conditioning system. Since the system is sealed and airtight, your refrigerant supply cannot evaporate or get used up. A low level of refrigerant means you’ve got a refrigerant leak somewhere, which should be repaired before your coolant is topped up. If you don’t have enough refrigerant, the air that’s circulating throughout your car’s air conditioner can’t cool down, and if it gets low enough, your air conditioning system will begin blowing warm air. 

Locating and fixing a refrigerant leak is a complicated task, best left to an auto repair professional. If you’re driving a pre-1995 vehicle, Ontario law makes it even more complicated; you must have it leak-tested by a technician with an Ozone Depletion Prevention certificate to ensure that you won’t be “discharging an ozone-depleting substance.”

SOLUTION: Sorry, there is no option for DIY here. As an Ottawa car owner, you’ll need a certified technician to handle this one.

3. Faulty Condenser 

The condenser is a vital component of your automobile air conditioning. Once the refrigerant has moved through the compressor, the job of the condenser is to bring it down to ambient temperature. 

The compressor’s position — at the front of your car between the radiator and the grille — allows air flowing through the grate to help with the cooling process. However, sometimes it also allows road dirt and debris to get trapped inside the condenser. The result will be a blockage or even breakage, such as the puncturing of one of the condenser tubes. A broken condenser means that the refrigerant isn’t able to stay at a temperature that allows it to cool air.

SOLUTION: Remove any sticks, small rocks, etc., from the grille. This simple DIY action might stop the problem of your AC blowing hot air and keep your car cool inside.

If not, take the car to a body shop. The system may need flushing or mechanical repair.

4. Bad Compressor

Your car’s AC compressor is responsible for pressurizing the refrigerant fluid and circulating it throughout the system of hoses and tubes to cool your car’s passenger cabin. As a hardworking component, the compressor is very vulnerable to failure due to wear and tear. In some car models, compressor failure can happen when you start it after a long period of inactivity — such as when you try to switch the air conditioning on for the first time in summer. A faulty compressor may cause your engine to overheat.

SOLUTION: Avoid compressor issues and keep it in good shape by turning on the air conditioner, set to HIGH, once every month, even if the outside temperature is already cold. If you’re dealing with a broken compressor, contact a body shop for repair.

5. Broken Cooling Fans

A pair of cooling fans form an important part of your car’s ventilation system. Their purpose is to help remove heat from the refrigerant fluid. If either of them becomes cracked or otherwise damaged — usually due to flying road debris — the refrigerant will not be adequately cooled, and before you know it, your air conditioner blows warm air into your car cabin.

SOLUTION: A broken cooling fan cannot be fixed. Get it replaced at a reliable auto body shop.

6. Dirty Air Filter

Some automobile makes and models are equipped with a cabin air filter. Just as with your HVAC filter at home, your car’s air filter gradually gets clogged with dust and debris, so regular changing is essential. A dirty air filter will not only cause poor airflow and inhibit air intake, but it can fill your vehicle’s cabin with musty, dusty smells that are unpleasant or even dangerous to your health. 

Besides hot air blowing from your vents, other signs that your cabin air filter could be blocked include musty smells or overly loud noises when you’re running the AC.

You may also notice your car stuttering or jerking when accelerating.

SOLUTION: You can buy a new filter and change it yourself; your owner’s manual will tell you how often it needs to be replaced. Or if you prefer, have the cabin filter changed for you as part of a professional auto tuneup.

Car AC Maintenance Tips

Regular maintenance of your car’s air conditioning will help it continue blowing cold air, and keep it running at top efficiency.

Run on Defrost Mode

Regularly switch your car’s AC to defrost mode for about 10-15 minutes, ideally once a week.

Why it’s important:

  • Running the defrost mode helps to reduce moisture buildup in the AC system, which can prevent mold and mildew from forming.
  • It keeps the internal components of the AC system, including the compressor and evaporator, operating properly by ensuring they are used regularly.

Clean Filter

Locate your car’s cabin air filter (usually found behind the glove box or under the dashboard). Remove the dirty filter and either clean it if it’s a reusable type or replace it if it’s disposable. This should be done every 12,000 to 15,000 miles or as recommended by your car’s manual.

Why it’s important:

  • A clean filter ensures that the air circulating in your car is free from dust, pollen, and other contaminants, improving the overall air quality inside the vehicle.
  • A dirty filter can restrict airflow, causing the AC system to work harder and less efficiently, which can lead to higher fuel consumption and potential damage to the AC components.

Keep Car Clean

Regularly clean your car’s interior, including seats, floor mats, and dashboard, to minimize dust and other debris. Pay special attention to the vents and duct openings, using a vacuum or a brush to remove any dust buildup. 

Why it’s important:

  • Keeping the car clean helps prevent dust and road debris from getting sucked into the ventilation system, which can clog the filters and reduce the system’s efficiency.
  • Clean interiors reduce any unpleasant odors, which can be exacerbated by the air conditioner circulating air throughout the car.

Don’t Leave Your Car AC Running

Avoid leaving the AC running when the car is off or when you’re idling for long periods. Instead, turn off the AC a few minutes before you reach your destination and allow the fan to run, which helps dry out the evaporator and reduce the risk of damage that will lead to blowing warm air.

Why it’s important:

  • Turning off the AC and letting the fan run helps to dry the system, reducing the risk of mold and mildew growth inside the AC ducts and on the evaporator.
  • Turning off the AC when it’s not needed helps save fuel and reduces wear and tear on the AC components, extending their lifespan.

Get Annual Car Tune-Ups

Schedule an annual tune-up with a professional mechanic to check your car’s AC system. This should include checking the refrigerant levels, inspecting hoses and belts, testing for leaks, and ensuring the compressor is functioning correctly.

Why it’s important:

  • Regular tune-ups can help identify and fix potential problems before they become major issues, saving you from costly repairs.
  • Ensuring all components of the AC system are in good working order helps maintain its efficiency, providing better cooling performance and extending the system’s lifespan.

Bemac Will Help Your Car Stay Cool

Come to Bemac for an auto tuneup or mechanical repair in the Ottawa-Gatineau area. We’ll take good care of your air conditioning so you stay cool and drive safe.

If your car is blowing hot air, get in touch with us for a free quote.