Hot air blowing from the air conditioner: possible causes and solutions

Many drivers notice that the air conditioner, instead of the promised coolness, starts blowing hot air. Most often, this happens due to refrigerant leakage — without it, the system simply cannot cool. But there are other factors affecting the air temperature in the cabin.

At speed, air from the outside enters the cabin almost unchanged, but in a traffic jam or at a standstill, it has time to warm up. Air inlets are usually located near the windshield, where heat from the engine and the hot body (especially dark-colored) raises the temperature of the incoming flow. Additional heating may be created by the heater, and if the exhaust manifold or turbocharger is close to the firewall, the air becomes almost scalding.

Modern climate systems are more complex than older models. Even in ventilation mode, air passes through the A/C evaporator, and heating goes through the heater radiator. Previously, mechanical taps were used for this, but now they have been replaced by automatic dampers. If one of them sticks or breaks, hot air can seep into the cabin even with the heater turned off.

Most often, the damper itself is to blame — it deforms or gets stuck. If the drive is electric, the problem may lie in the servo: this will require diagnostics and possibly replacement. In some cases, reflashing the climate control unit helps, but this is already a job for specialists.