What is the temperature of the water circulating in an underfloor heating system?
Floor Microclimat / August 14, 2025
Contrary to what one might think, the water circulating in an underfloor heating system
is not very hot. We are not talking about boiling water as in a traditional radiator
.
In general, it is between 30°C and 45°C.
Why is it so “lukewarm”?
Because underfloor heating distributes heat over a large surface area (the entire floor of the room). It therefore does not need to reach very high temperatures to heat effectively and comfortably.
Here are some specific examples:
- Well-insulated house + heat pump: The water temperature is around 30 to 35°C. This is perfect: comfortable, economical, and great for the environment.
- House with a conventional boiler (gas, oil, etc.): The temperature is often between 35 and 45°C. This is still very acceptable and comfortable.
- Old, poorly insulated house: The temperature can be raised a little higher, sometimes up to 50°C, but this is not ideal: it consumes more energy and loses some of its “gentle heating” qualities.
And on a daily basis?
You don't need to manage this manually. The system adjusts the temperature automatically, based on the outside temperature, the rooms, and the temperature you want.
In summary:
- The water is warm, not hot.
- This provides gentle, even, and pleasant heat.
- And above all, it's good for comfort and your energy bill.