For heat, I need the recirculation on?

It is not necessary to turn on the recirculation setting when using the heater in your car. Recirculation mode is typically used to reduce the amount of outside air that enters the vehicle, which can be helpful in cooling the car down on a hot day. However, when using the heater, you want to draw in as much outside air as possible to ensure that the warm air is evenly distributed throughout the cabin. If you have the recirculation setting turned on, the hot air will only circulate within the car and may not reach all areas, leaving some passengers feeling cold.

Therefore, it is recommended to turn off the recirculation setting when using the heater in your car to ensure optimal heat distribution and passenger comfort.