Home heating: Coordinating underfloor and radiator systems

Managing mixed heating systems requires careful coordination between underfloor heating and traditional radiators. While both use warm water, they operate at significantly different temperatures. Radiators typically require higher water temperatures, sometimes up to 70 or 80 degrees Celsius, to release heat effectively. In contrast, underfloor heating operates at much lower temperatures, generally between 30 and 45 degrees Celsius, to prevent surface overheating and ensure comfort. Proper planning must include regulated water flow and independent control loops to prevent temperature imbalances between rooms.

To maintain heating efficiency, users should also perform radiator bleeding before the winter season. Trapped air in radiators can cause uneven heating and increased boiler workload. To bleed a radiator, the system must first be turned off and allowed to cool completely to avoid burns. Using a radiator key, air can be released through the valve—usually located at the top corner—until a steady stream of water appears. It is recommended to start with the radiators furthest from the boiler to ensure the entire system is addressed.