Yes, radiator valves are specifically designed to control the flow of hot water into radiators. They regulate the amount of hot water entering a radiator, thereby controlling the heat output. There are two main types of radiator valves: manual and thermostatic. Manual radiator valves allow for basic control, letting users manually adjust the flow of hot water into the radiator. Thermostatic radiator valves (TRVs), on the other hand, automatically adjust the flow based on the room's temperature, providing a more consistent level of warmth and potentially improving energy efficiency by reducing the heat output when the desired temperature is reached.