Why Does the Car Air Conditioner Blow Hot Air When Set to Cool?
3 Answers
The reasons why a car air conditioner blows hot air when set to cool are as follows: 1. Lack of refrigerant: Check if the outdoor unit of the air conditioner still has refrigerant. If not, refrigerant needs to be added. If there is a refrigerant leak or it has been depleted, the system will blow hot air. 2. Compressor not working: Feel the outdoor unit's air outlet to check if there is hot air. If not, it is likely that the thermal protection has caused the compressor to stop working, resulting in the air conditioner not cooling despite being set to cool. 3. Damaged computer motherboard: Check the settings on the remote control. If the mode is correct, the issue might be a faulty four-way valve or a damaged computer board. It is recommended to contact after-sales service for repair.
I've been driving for over twenty years, and encountering hot air blowing from the AC is a common occurrence. The most frequent reasons are refrigerant leaks or insufficient levels, much like gas leaking out of a can. If the compressor fails and stops running, the entire system shuts down. Blockages in the pipes or evaporator, along with dust buildup, can also cause hot air to emerge. A malfunctioning temperature control switch might misread the temperature, turning cold air into hot. I recommend first checking the refrigerant pressure—if it's too low, top it up promptly. Cleaning the condenser once before summer can prevent blockages. Don’t overlook this; high cabin temperatures can easily cause drowsiness, posing significant safety risks. During routine maintenance, take the opportunity to test the AC system—it’s cost-effective and ensures peace of mind.
Last time my car's AC suddenly started blowing hot air, and it was unbearable. It took me a while to figure out the issue. Most of the time, it's because the refrigerant has leaked or the compressor has stopped working. Loose wiring or blown fuses are also common. If the fan malfunctions and heat dissipation is poor, the cold air disappears. Try checking the blower and belts yourself. If they don't work, get them fixed immediately—delaying repairs can be dangerous when driving. After the repair, fuel consumption noticeably dropped. Now I've learned to check the refrigerant level every season, not waiting until problems arise to deal with them.
