Akademik

water heater consisting of a tank or pipes set at the back of a fireplace or in the firebox of a stove

1. : a cistern used in brewing for storing hot or cold water

2.

a. : a reservoir at the back of a wood or coal range for heating and storing water

b. : a system of tubes often enclosed in a solid casting, placed in the firebox of a wood or coal range on the side opposite the oven for heating water, and connected with a storage tank separate from the range

a reservoir or arrangement of tubing at the back of certain stoves or fireplaces for containing water to be heated by the fire.

[1860-65, Amer.]

water back,

a tanklike receptacle or reservoir for heating water, built into the back of a wood or coal stove.