Q: Air conditioning started blowing hot air

There are many components that allow the air conditioner in your Mercedes to blow ice cold on days when you need it the most, but without a bit more information it is difficult to determine if the A/C compressor is in need of replacement. The A/C will blow hot if the system has developed a leak, such as when a rock or road debris makes its way beyond the grill on your bumper, causing damage to the A/C condenser. It is also possible that one of the blend doors that allow you to switch from hot to cold air has failed and is only providing hot air. To be certain what is causing your A/C to emit only hot air, it may be time to enlist the assistance of a certified mechanic. They will be able to determine why your A/C is not operating and perform the necessary repairs to keep the car cool on those hot days.