Why it takes time and what you can do about it.
One of the most common criticisms of underfloor heating is that it takes a long time to warm up. Unlike radiators, which can heat a room quite quickly, underfloor heating is designed for steady, consistent warmth rather than rapid temperature changes.
However, if it feels excessively slow, there are usually reasons why — and some of them can be improved.
Screed systems in particular have a lot of thermal mass. The concrete or screed needs to heat up before it can effectively warm the floor surface. This is normal and part of how the system works.
If the system is designed to run at very low temperatures (which is efficient), it will naturally take longer to warm up. Higher flow temperatures heat the floor faster but reduce overall efficiency.
Thick carpets, underlays, or certain vinyls can slow down heat transfer from the floor to the room. Tiles and engineered wood generally allow heat through more quickly.
If there’s poor insulation underneath the heating pipes, a lot of heat is lost downward instead of rising into the room. This is especially common in older properties with suspended timber floors.
If the system is only turned on when you need heat (rather than running steadily), it will take much longer to reach a comfortable temperature. Underfloor heating works best when left on for longer periods.
Instead of turning the heating on and off, try running it at a lower temperature for longer periods. This is how underfloor heating is designed to work and usually feels more comfortable.
If you have thick carpets or unsuitable underlay, consider changing to something more heat-friendly. This can make a noticeable difference to warm-up times.
Make sure the system is set to come on earlier than you think you need it. Many people underestimate how long it takes to warm up from cold.
If warm-up times seem unusually long, have an installer check flow temperatures, flow rates, and manifold settings. Sometimes adjustments can improve performance.
Use our Underfloor Heating Calculator to get recommendations based on your floor type and project.