There’s nothing quite like stepping into an air-conditioned car on a hot day—until your car aircon starts blowing warm air instead of a refreshing chill. If your car air conditioning is not cold, or your car AC stops working altogether, you’re not alone. Thousands of drivers experience issues with their car air conditioning systems, especially during peak summer months.
In this guide, we’ll explore the most common reasons why your car aircon is not blowing cold air, how to diagnose the problem, and when it’s time to book a car air conditioning recharge or car air conditioning repair. Whether your car AC blows cold air then hot, or it’s only cold when moving, we’ve got practical tips to help you stay cool on the road.
Before diving into troubleshooting, it helps to understand how the AC system works in a car. Your car’s air conditioning relies on a closed-loop system that circulates refrigerant to absorb heat and cool the air. Key components include:
- Compressor: Pressurises the refrigerant and circulates it through the system.
- Condenser: Removes heat from the refrigerant.
- Expansion valve: Regulates refrigerant flow.
- Evaporator: Absorbs heat from the cabin air.
- Refrigerant (AC gas): The chemical that cools the air.
When any part of this system fails, you may notice your car AC not blowing cold air, or the car air conditioning going hot and cold.
How cold should air conditioning be in a car?
A properly functioning car air conditioning system should cool the cabin to around 4–8°C below ambient temperature. If your AC isn’t reaching these levels, it’s time for a check-up.
1. Low refrigerant or AC gas leak
One of the most frequent causes of poor cooling is low refrigerant levels, often due to a car AC leak. Over time, refrigerant can escape through seals or tiny cracks in the system, reducing cooling performance.
If your car aircon is not cold, or your car AC blows air but not cold, it’s likely time for a car AC gas refill. A professional technician can check for leaks and recharge the system.
Signs of low refrigerant:
- Gradual loss of cooling
- Hissing sounds from the AC system
- Oily residue around AC components
Most manufacturers recommend a car air conditioning recharge every two years. Even without a leak, refrigerant levels drop over time, reducing cooling efficiency, so why not book a car air conditioning recharge today.
2. Compressor faults
The compressor is the heart of your car’s AC system. If it fails, the refrigerant won’t circulate, and the system won’t cool. Compressor issues can be mechanical or electrical, and they often require professional repair.
Symptoms of compressor failure:
- No cold air even after a recharge
- Loud noises when AC is on
- AC clutch not engaging
If your car AC stopped blowing cold air suddenly, or the system is making unusual sounds, it’s time to consider a car air conditioning repair.
3. Blocked cabin air filter
A dirty or clogged cabin air filter can restrict airflow, making it seem like your AC isn’t working—even if the system is fine. This is a simple fix that can dramatically improve performance.
Tip: Replace your cabin air filter every 12,000–15,000 miles or once a year to keep your air-conditioned car running efficiently.
4. Electrical or sensor issues
Modern car air conditioning systems rely on sensors and electronics to regulate temperature and pressure. A faulty pressure switch, blown fuse, or wiring issue can cause the AC to malfunction.
If your car AC blows cold air then hot, or the system only works intermittently, an electrical fault may be to blame. A diagnostic check can pinpoint the issue quickly.
Before heading to the garage, there are a few things you can check yourself:
- Feel the air: Is it warm, cool, or fluctuating?
- Listen for noises: Clicking or grinding sounds can indicate mechanical issues.
- Check for leaks: Look for oily residue around AC pipes or connectors.
- Smell the air: A musty smell could mean mould in the system or a dirty filter.
If you’re wondering how to fix car AC not blowing cold air, start with these simple checks. If the problem persists, it’s time to book a professional inspection.
Whether you need a car air conditioning recharge, a car AC gas refill, or a full car air conditioning repair, Eurorepar Car Service offers expert solutions at competitive prices. With garages across the UK, we’re here to help you stay cool and comfortable on the road. So why not book your air conditioning service today!
