If you’ve ever turned on your BMW’s AC only to feel hot air blowing from it, you’ll want to know the reasons why and how to fix it. First, a BMW’s air conditioner operates using a refrigeration system that uses a special gas called a refrigerant. This is compressed and cooled by the car’s compressor, which converts it into a high-pressure gas. The gas then moves to the condenser, which is located in front of the engine’s radiator. The condenser cools the gas down by releasing the heat, turning it into a liquid.
The liquid refrigerant then moves to the evaporator located inside the car’s cabin, where it absorbs the heat from the surrounding air, thereby cooling it down. This air is circulated back into the cabin through the air vents, while the heated refrigerant returns to the compressor to repeat the cycle.
A BMW’s air conditioner features automatic temperature control, allowing passengers to set the desired temperature, and the system will maintain it by adjusting the refrigerant flow and blower speed accordingly, as long as it’s working properly. If not, it can get hot real fast. Not only is it uncomfortable to drive in hot temperatures, but it can also be dangerous if you’re driving in extreme heat. Overheating can cause fatigue, dizziness, and even fainting, which can lead to accidents on the road. Let’s look at the most common causes of hot air from a BMW’s air conditioning system.
Low Refrigerant Levels
The most common reason your BMW AC might be blowing hot air is due to low refrigerant levels. Refrigerant is what cools the air that comes through your AC, and when levels are low, the air won’t be as cool as it should be. This can happen over time as the refrigerant leaks out of the system, or it could be due to a more significant issue with the AC system.
To fix this issue, you’ll need to bring your BMW to our professional to have the refrigerant levels checked and topped off. It is important to check for any leaks in the system that could be causing the low refrigerant levels.
Faulty AC Compressor
Another reason your BMW AC might be blowing hot air is due to a faulty AC compressor. The compressor is responsible for compressing the refrigerant and circulating it through the AC system, and if it’s not working correctly, it won’t be able to cool the air. This is a more significant issue that will likely require our mechanic’s expertise to fix. There will be a need to diagnose the issue and determine if the compressor needs to be repaired or replaced.
Electrical Issues
In some cases, electrical issues could be the cause of your BMW AC blowing hot air. There are many electrical components involved in the AC system, including the AC relay, fuse, and blower motor. If any of these components are not working correctly, it could prevent the AC from cooling the air. An electrical diagnosis has to be performed to determine the cause of the issue. The faulty component may need to be replaced and the damaged wiring repaired.
Clogged or Dirty Condenser
Condensers are responsible for bringing out heat from the refrigerant, and when they become clogged or dirty, they won’t be able to function properly. This can result in an AC blowing hot air instead of cool air. To fix this issue, It’s important to have your condenser properly cleaned or replaced. Our mechanic can perform this service for you, and it’s recommended to have it done every few years to keep your AC functioning correctly.
Broken Temperature Sensor
The temperature sensor in your BMW is responsible for detecting the temperature of the air coming out of the AC and adjusting the cooling accordingly. If the sensor is broken or malfunctioning, it may not be able to accurately detect the temperature, causing your AC to blow hot air. This issue needs to be fixed by testing the sensor and replacing it if necessary.
DART Auto Will Maintain Your BMW’s AC!
At DART Auto, we are always here to help lift 
the burden of malfunctions and get you back on the road, driving with confidence in your BMW again. Our technicians are highly trained with decades of experience in working with BMW models. We are always pleased to serve the residents of Englewood, Centennial, Littleton, and Denver, CO. Call us today to book an appointment or stop by to visit us and speak with our friendly staff.
