How to Select a Heating Circulation Pump: Flow, Head and Temperature Difference

When selecting a heating circulation pump, power is the last thing to look at. First calculate the flow from the heat load and the design temperature difference (flow ≈ load kW × 0.86 ÷ ΔT), then estimate the head from the resistance of the longest circuit — for most residential heating systems this is only about 2–6 m. Finally pick a model whose duty point sits in the middle of its performance curve. Variable-speed series such as Wilo Yonos and Stratos adjust automatically when thermostatic valves open and close. You can compare the official data on our Wilo product pages, or send us your heat load and pipe layout and we will check the selection for you.