The operating principle of the Enduce E1 is that it preheats the incoming cold water to the shower with the heat from the used shower water. But it is perfectly possible to take a cold shower anyway. When you adjust the mixer to colder shower water, less hot water is mixed into the shower water - colder water ends up in the floor drain - and less heat is transferred from the outgoing shower water to the incoming cold water. As a result, the shower mixer in combination with the floor drain quickly reduces the temperature of the shower water and enables cold showers.
