How about this analogy: You have a tap with a hot handle and a cold handle. You can make medium lukewarm water by making hot and cold equally strong. To mainta

How about this analogy: You have a tap with a hot handle and a cold handle. You can make medium lukewarm water by making hot and cold equally strong. To maintain temperature but increase flow, you must increase both handles After DCT, the tap instead has a handle controlling the temperature, and another handle controlling the flow. You can make all the same combinations of flow and temperature, but it's controlled in a different way. Medium lukewarm water is now made by having the temperature handle halfway, and the flow then increased by increasing only the other handle. Not sure if this analogy works for America since American showers have, afaik, a single rotational dial that somehow controls both temperature and flow (???), but in Europe the distinction between the sinks with a red and a blue handle, vs the thermostatic tap with temperature handle and flow handle, is very common :)