Question 1

What is the difference between wet and electric underfloor heating?

Accepted Answer

Wet (hydronic) underfloor heating uses warm water circulated through pipes embedded in the floor, connected to your boiler or heat pump. It is more efficient to run than electric for whole-room or whole-home heating. Electric underfloor heating uses heating elements embedded in the floor and is easier and cheaper to install — making it popular for retrofitting in single rooms such as bathrooms. Running costs for electric are higher.

Question 2

How much does underfloor heating cost to run?

Accepted Answer

Wet underfloor heating connected to a condensing gas boiler costs broadly similar to radiator-based heating to run, sometimes slightly less due to the lower flow temperatures involved. Electric underfloor heating costs more per unit to run than gas but is often used in small areas where convenience outweighs running cost. Heat pump-driven wet underfloor heating is very efficient as heat pumps perform best at the low flow temperatures underfloor systems use.

Question 3

Is underfloor heating compatible with a heat pump?

Accepted Answer

Wet underfloor heating is arguably the ideal heat distribution system for an air source heat pump. Heat pumps work most efficiently at low flow temperatures (around 35–45°C), which is exactly the range that underfloor heating systems operate at. This combination can achieve COP values of 4 or higher, significantly reducing running costs compared to radiators.

Question 4

How disruptive is underfloor heating installation?

Accepted Answer

New-build installation is straightforward as pipes are laid before the screed is poured. Retrofit wet underfloor heating is more disruptive as it involves lifting floor coverings and either lowering the sub-floor or overlaying with a thin system. Some modern low-profile retrofit systems add as little as 15mm to the floor height. Electric systems require only the removal and replacement of floor tiles or coverings — less disruptive overall.

Question 5

Can underfloor heating be retrofitted in an existing home?

Accepted Answer

Yes, but it requires careful planning. In ground floor rooms with solid concrete floors, a retrofit screed system is most common. In rooms with timber suspended floors, pipes can be fitted between or below the joists. Thin overlay electric systems work well under tiled floors in single rooms. We'll assess your specific floor construction and recommend the most suitable approach.

Question 6

How is underfloor heating controlled?

Accepted Answer

Each room or zone of underfloor heating is typically controlled by its own thermostat, allowing independent temperature control. Manifolds distribute water to each circuit and are fitted with actuators controlled by the thermostats. Modern systems can be integrated with smart home platforms, allowing app control, scheduling, and geofencing. A weather compensation controller connected to the heat pump or boiler optimises flow temperatures automatically.

Question 7

How quickly does underfloor heating warm a room?

Accepted Answer

Underfloor heating has a slower response time than radiators, typically taking 1–3 hours to reach operating temperature from cold. This is because the entire floor mass must be heated. For this reason, underfloor heating is best used on a continuous low-temperature schedule rather than in short bursts — setting it to maintain a minimum temperature 24/7 is more efficient than heating from cold morning and evening.

Question 8

What floor coverings are compatible with underfloor heating?

Accepted Answer

Tile and stone are the best conductors and most efficient with underfloor heating. Engineered wood is generally compatible (check manufacturer's maximum temperature specifications). Solid hardwood can be used with care but requires stable low flow temperatures. Most vinyl and LVT products are compatible. Thick carpet and underlay significantly reduces heat output and is not recommended. Check manufacturer specifications for any floor covering before installation.

Underfloor Heating FAQs