Underfloor heating (UFH) is becoming increasingly popular in new-build and renovation projects. But does it work with any boiler, or do you need a specific setup?
How underfloor heating works
Wet underfloor heating circulates warm water through pipes embedded in the floor. It works at much lower temperatures than radiators — typically 35–45°C flow temperature, compared to 70–80°C for radiators. This makes it inherently more efficient with condensing boilers, which perform best at low return temperatures.
Is your boiler compatible?
Any modern gas boiler can technically supply underfloor heating. However, to achieve the best efficiency:
- The boiler needs to be able to modulate down to a low flow temperature (most modern boilers can)
- A weather compensation controller is recommended to automatically adjust flow temperature
- A blending valve (mixing valve) may be needed if you're mixing UFH zones with conventional radiators
Mixing UFH and radiators
Many homes have UFH in ground floor rooms (kitchen, bathroom) and radiators upstairs. This works well but requires a low-loss header or hydraulic separator to balance the two circuits at different temperatures.
UFH and heat pumps
If you're considering a future move to an air source heat pump, UFH is the ideal partner — heat pumps work at exactly the low temperatures that UFH requires. Installing UFH now, even with a gas boiler, makes any future heat pump switch more cost-effective.