The additional heater is one of two subfunctions of the car's heater. The heater is fitted in the front right-hand wheel housing.
When the heater is running, smoke may be emitted from the right-hand front wheel housing and a low hum may be heard. A ticking sound from the fuel pump may also be heard from the rear section of the car. This is perfectly normal.
The additional heater starts and is controlled automatically when heating is required while the car is being driven.
It switches off automatically when the car is switched off.