There could be several reasons why the inside of your car feels excessively hot even when the heat is turned off. Here are a few possible explanations:
Sunlight and heat transfer: If your car is parked in direct sunlight, the windows can act as a greenhouse, allowing sunlight to enter but trapping the heat inside. This can cause the interior temperature to rise quickly, even if the heat is turned off.
Insulation issues: Poor insulation or seals around the windows, doors, or roof can allow external heat to enter the car easily. Additionally, damaged or worn weatherstripping can contribute to heat penetration.
Engine heat transfer: If there is a problem with the heat shielding or insulation in the engine compartment, excessive heat generated by the engine may transfer to the cabin area, making it feel hotter than it should.
HVAC system malfunction: The heating, ventilation, and air conditioning (HVAC) system in your car could be malfunctioning, causing it to blow hot air into the cabin even when the heat is turned off. This can happen due to a faulty control module, a stuck blend door, or other issues with the HVAC system.
Recirculation settings: Ensure that the recirculation mode is turned off. When this mode is activated, the HVAC system recirculates the air inside the car instead of drawing in fresh air from outside. If the air inside the car is already hot, it will continue to circulate and make the interior feel hotter.
If you are experiencing this issue, it's recommended to have your car inspected by a qualified mechanic. They can diagnose the problem accurately and recommend the necessary repairs to resolve the excessive heat inside your car.