How much water does the hot tub need before I can start heating?

The hot tub must be filled to at least this level before you start heating. In this way, the stove is filled with water. If you do not do this, the stove will not be able to cool itself and will break down. Before you start heating, it is important that the hot tub is filled with water to the correct level. The landmark for this is the Ducktub sticker on the inside of the tub. This sticker sits about 10 centimeters below the edge and is specially placed to show you where to fill.

Why is this so important? If the water level is too low, the internal wood stove will dry. Then water no longer flows through the coil, so that the stove cannot cool itself. This can lead to overheating, damage to the heater and, in some cases, even permanent deformation or leakage.