Why won't my 40L Sparge Water Heater boil when it is set to 100°C (212°F)?
The unit will boil when set to 100°C (212°F), but you'll need to keep the element on and high in order for it to keep boiling.
To keep the water at 100°C (212°F), you must keep the element on, which can be done by setting the unit to 110°C (230°F). You will see the dial goes up to 110°C (230°F).