What Temperature Should Underfloor Heating Be Set At

Underfloor heating is becoming increasingly popular across UK homes, not only for the comfort it brings but also for the efficiency it offers compared with traditional radiators. One of the most common questions asked by homeowners, landlords, and developers is what temperature underfloor heating should be set at. The answer depends on the type of system, the floor finish, and how the property is used, but there are some clear guidelines that can help you make the right choice. Setting the correct temperature ensures a balance between comfort, efficiency, and safety.

How Underfloor Heating Works

Underfloor heating can be powered either by water pipes connected to a boiler or heat pump, known as wet underfloor heating, or by electric mats and wires, known as dry systems. In both cases, heat is distributed evenly across the floor, warming the space from the ground up. Because the heat rises gradually and covers a larger surface area, underfloor heating can usually operate at lower temperatures than radiators while still keeping a room comfortable.

This difference is one of the main reasons underfloor heating is often considered more efficient. Radiators may need to reach 65 to 75°C to heat a room effectively, whereas underfloor heating typically operates between 25 and 40°C depending on the system and room conditions.

Ideal Floor Surface Temperatures

The recommended surface temperature for underfloor heating is usually between 27 and 29°C for most floor finishes. This is warm enough to provide comfort underfoot without overheating the room or causing issues with floor coverings. For tiled or stone floors, which conduct heat well, the upper end of this range is often used. For wooden floors, the temperature should be kept lower, generally no higher than 27°C, to avoid warping or damage to the material.

Carpets can also be used with underfloor heating, but their insulation properties can reduce efficiency. In such cases, the heating system may need to run slightly warmer, though care should still be taken to ensure the carpet and underlay are compatible with underfloor heating systems.

Room Temperature Settings

While the floor temperature is important, what ultimately matters for comfort is the air temperature within the room. For living rooms and general living spaces, an air temperature of around 20 to 22°C is considered ideal. Bedrooms are often kept slightly cooler at 18 to 20°C, which supports better sleep. Bathrooms, where people prefer extra warmth, are often set between 22 and 24°C.

Thermostats designed specifically for underfloor heating help to regulate both floor and air temperatures. Modern systems often include programmable thermostats, allowing you to set different zones in the home at different temperatures, which maximises efficiency and reduces energy bills.

Balancing Comfort and Efficiency

Running underfloor heating at excessively high temperatures is not only unnecessary but can also be counterproductive. Since the system heats slowly and retains warmth in the floor mass, lower consistent temperatures are usually more effective than short bursts of high heat. Overheating can increase energy costs and may lead to uncomfortable conditions, especially in well-insulated homes.

For most systems, setting the water flow temperature between 35 and 45°C is sufficient, which then translates into a floor surface temperature of around 27°C. Electric systems usually come with built-in controls to prevent overheating, ensuring the temperature stays within safe and effective limits.

Underfloor Heating in Different Property Types

In older properties with less insulation, slightly higher settings may be required to compensate for heat loss. However, in modern homes built to higher efficiency standards, lower temperatures are usually more than adequate. Developers often choose underfloor heating in new builds because it integrates seamlessly with insulation requirements under UK Building Regulations, making it both efficient and comfortable.

For landlords, ensuring that underfloor heating is correctly set and maintained is important not just for tenant comfort but also for compliance with minimum energy efficiency standards. A system that is poorly set can lead to wasted energy and higher bills, which may cause disputes with tenants.

Safety Considerations

Safety is a key factor in temperature settings. Floors that are too hot can be uncomfortable and potentially harmful, especially for vulnerable people such as young children or elderly residents. Overheating can also damage floor coverings, particularly natural wood, which can warp if exposed to temperatures above recommended limits.

Using thermostats with built-in floor sensors helps to prevent these risks. It ensures the system never allows the floor to exceed safe levels, protecting both the property and its occupants.

Best Practice for Everyday Use

The best approach with underfloor heating is to treat it as a constant low-level heat source rather than something that should be switched on and off like a radiator. Because it takes longer to heat up and cool down, leaving it running at a steady temperature is usually more efficient. Many modern systems allow for smart scheduling so that heating can reduce slightly at night or when the property is unoccupied, but without dropping too low and forcing the system to work harder to reheat.

Final Thoughts

The ideal setting for underfloor heating depends on the type of system, the room in question, and the floor covering used. As a rule, floor surface temperatures should be around 27°C, with room temperatures varying between 18 and 24°C depending on use. Keeping the system running at steady, moderate temperatures provides the best balance of comfort and energy efficiency. For homeowners, landlords, and developers alike, understanding how to set underfloor heating correctly helps ensure both cost-effective performance and a comfortable living environment.