The Heat exchanger circulates the water tank water through natural convection, hot water rises up. Therefore the Heat Exchanger must below the water tank. The cooler water flows down and then the heated water flows up to the tank.
Material: 4 mm thick Steel, painted black
The watertank must be placed higher than the heat exchanger, in order to avoid an air bubble, an air lock, in the heat exchanger. Place the heat exchanger fully against the Hive heater fireplace body, before the stones, and during inserting the rocks make sure the heat exhanger remains against the heater.