Abstract: A modular heating system for large vehicles. At least one elongated heating element module is suitable for horizontal mounting along an interior wall and near the floor of the vehicle. The heating element module includes a convector including at least one essentially longitudinally extending pipe arranged to conduct a heating medium. The pipe is provided with a plurality of mutually spaced fins transversely mounted thereto. The system further includes at least one blower module including at least one fan. The blower module is selectively attachable to the heating element module at an arbitrary position along the extension thereof adjacent to the fins and further arranged to be selectively operable to produce a forced airflow through the plurality of fins in a direction from a side of the convector intended to be mounted facing upwards towards a side thereof intended to be mounted facing downwards.