A three on the radiator is not heating power. What do the numbers on the thermostat really mean?

The thermostat head does not control the heating power but sets the desired air temperature. The numbers indicate target temperatures, with 3 roughly equating to 20°C. Higher settings do not heat rooms faster; they only delay valve closure until the room reaches the set temperature. This can lead to overheating and increased energy consumption. Proper placement and avoiding obstructions around the thermostat are crucial for accurate readings. Experts recommend different temperatures for various rooms to optimize comfort and energy savings, with each degree reduction potentially lowering heating costs by 6-8%.