Best temperature for bathroom underfloor heating
Stepping barefoot onto warm tiles on a cold morning: once you’ve had it, you won’t want to go back. At the same time, you don’t want your electricity bill to shoot up. The good news is that with the right temperature and a heating schedule, you can have both.
The short answer: for a pleasantly warm feel underfoot, a floor temperature of 24 to 27 °C is enough. When nobody is using the bathroom, drop it to 18 to 20 °C or switch it off altogether.
Floor temperature is not room temperature
These two often get mixed up. The floor temperature is the temperature of the tiles you feel with your feet. The room temperature is the air temperature in the bathroom. A floor at 26 °C feels warm, while the air may only be 22 °C.
Which one your thermostat controls depends on its sensor:
- Floor sensor: measures the temperature in the floor. Ideal when the underfloor heating is mainly there for warm feet and a radiator or towel rail heats the room.
- Air sensor: measures the air temperature. Useful when the underfloor heating is the only heat source in the bathroom.
- Both combined: the thermostat controls the room temperature and limits the floor temperature at the same time. The best choice for sensitive floor coverings.
Most Wi-Fi thermostats for electric underfloor heating work with a floor sensor and can also be set to control the room temperature.
Recommended settings for your bathroom
| Situation | Setting | Note |
|---|---|---|
| Showering, brushing teeth, getting ready | Floor 24 to 27 °C | Feels warm without being uncomfortably hot. |
| Underfloor heating as the only heat source | Room 22 to 24 °C | Ideally with a floor temperature limit. |
| Nobody in the bathroom (daytime, night) | Floor 18 to 20 °C or off | The better the floor is insulated, the more it pays to switch off completely. |
| Vinyl, LVT, laminate or wood | Floor 27 °C maximum | Check the flooring manufacturer’s instructions. |
| Holiday or longer absence | Off or frost protection | In a heated home, off is usually fine. |
For reference: bathrooms are usually designed for a slightly higher room temperature than living rooms, typically around 22 to 24 °C.
How warm can the floor get?
Underfloor heating in the UK follows the European standard BS EN 1264. It sets a maximum surface temperature of 29 °C for occupied areas and 33 °C for bathrooms. Above that, it quickly becomes uncomfortable.
The limit for your floor covering is often lower. Tiles and natural stone handle higher temperatures without any problem. For vinyl and PVC, laminate and engineered wood, the limit is usually 27 °C. Set the floor limit on your thermostat accordingly.
When should the heating switch on?
Electric underfloor heating responds quickly, but not instantly. How long it takes depends mainly on what is underneath. If the heating mat sits on insulation boards, the floor is often warm within 15 to 30 minutes. Directly on concrete, it can take 45 to 90 minutes or longer. Read more in our article on insulation under electric underfloor heating.
In practice: let the heating come on about 30 minutes before you get up, and again shortly before your evening shower. A weekly schedule on the thermostat does this automatically.
What does a warm bathroom floor cost?
Consumption depends on floor area, insulation, set temperature and the weather outside. Because the thermostat cycles on and off, electric underfloor heating uses on average roughly 0.05 to 0.08 kWh per m² per hour in winter. For a 5 m² bathroom, we calculate with 0.06 kWh per m² per hour and an electricity price of 26.32p per kWh (Ofgem price cap, October to December 2026).
| Use | Consumption per day | Cost per day | Cost per month |
|---|---|---|---|
| Schedule, 3 hours a day | 0.9 kWh | 24p | about £7 |
| Left on, 24 hours a day | 7.2 kWh | £1.90 | about £57 |
Rough guide figures, excluding the standing charge you pay anyway.
The difference shows where the real savings are: not so much in one degree more or less, but in only heating when you actually use the bathroom.
Five tips for a warm bathroom and a low bill
- Use a weekly schedule. Warm when you get up and shower, set back or off the rest of the time.
- Don’t set it higher than you need. A higher setting won’t heat the floor any faster, because the mat already runs at full power until the target is reached.
- Insulate under the heating mat. Less heat goes into the subfloor and the floor warms up faster.
- Choose the right output. 150 W/m² is common for bathrooms. In our complete sets, mat and thermostat are matched.
- Consider a time-of-use tariff. With a smart meter and a time-of-use tariff, early-morning heating can fall into cheaper hours.
Conclusion
Set the floor to 24 to 27 °C while you use the bathroom, then drop it to 18 to 20 °C or switch off. Keep vinyl, laminate and wood at 27 °C maximum. With a schedule and insulation under the mat, you get a warm bathroom without a shock on your energy bill.
Wondering how running costs compare with gas? Read Electric underfloor heating vs gas: what costs more? Or explore our electric underfloor heating for bathrooms.
