You will need to drain the central heating system before you replace the radiator.

你得先把中央供暖系统的水排净再更换散热器。

《牛津词典》

Energy use refers to energy consumers - the central heating system, mainly referring to the building heating, generally pass through the radiator to heat the room.

热能使用是指热能的消费者——在集中供热系统中主要指建筑物的采暖，一般通过散热器把热能传给房间。

youdao

Ally read novels, wrapped up in her duvet beside the central-heating radiator in her bedroom, borrowing them from the center and the public library, sometimes finishing one and starting another without even changing her position or getting up to make coffee, like an addict.

NEWYORKER: She��s the One