It cools the car; warms the house (8)
I believe the answer is:
radiator
This clue could be a double definition.
'it cools the car warms' is the first definition.
The definition suggests a singular noun which matches the answer.
'house' is the second definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'the' acts as a link.
Can you help me to learn more?
(Other definitions for radiator that I've seen before include "House-warmer; engine-cooler" , "Domestic heat source" , "Room warmer" , "It distributes heat in home, filled with hot water" , "It spreads heat around room or cools engine" .)