Verses with the word coals in the New Testament (3 verses):

John 18:18
And the servants and officers stood there, who had made a fire of coals; for it was cold: and they warmed themselves: and Peter stood with them, and warmed himself.

John 21:9
As soon then as they were come to land, they saw a fire of coals there, and fish laid thereon, and bread.

Romans 12:20
Therefore if thine enemy hunger, feed him; if he thirst, give him drink: for in so doing thou shalt heap coals of fire on his head.