The Alde central heating system works with heat transfer fluid and is based on the same principles as the systems found in homes. The convectors located next to the exterior walls heat the air, which then rises and warms the walls and furniture. The rising hot air creates an air barrier in front of the windows which blocks the cold air. After the hot air reaches the ceiling, it cools and returns to the floor, where it is heated once again by the convectors.

ALDE heating is installed as standard on the 80LMS A-Class models and available as an optional extra on the 70LJG, 74LMS, 74LJT and 75LMF A-Class models.