The short answer
Underfloor heating is not inherently expensive to run — a wet system is usually cheaper to run than radiators, while an electric system can be expensive if used to heat a large area for long periods. The reason is efficiency: a wet system heats the whole floor at a low temperature, which suits a boiler or heat pump, so the cost of heat is low. An electric mat costs more per unit of heat, so it is economical for a small bathroom warmed occasionally but expensive for a whole house run all day. The system type and how you use it decide whether it feels cheap or costly. These are general illustrations, not a forecast of your bills.
“Expensive to run” is one of the most common worries about underfloor heating, and the reputation comes mostly from electric systems used in the wrong place. This guide separates the two system types, explains when each is economical and when it is not, and sets out the things that keep running costs down. All figures are general illustrations, not a quote or a promise of savings, and underfloor heating should be fitted by a Gas Safe registered heating engineer (wet) or a NICEIC registered electrician (electric).
Expensive to run? At a glance
- Wet, daily whole-house Usually cheaper than radiators
- Electric, small room occasional Economical
- Electric, large area all day Can be expensive
- Cheapest pairing Wet + heat pump
- Biggest factors Insulation, heat source, use
- Controls Programmable / smart helps
When underfloor heating is cheap to run
A wet underfloor heating system warms a large surface at a low flow temperature, so it reaches a comfortable room temperature using less energy than radiators that rely on a small, hot surface. That low temperature is efficient for a condensing boiler and ideal for a heat pump, which delivers several units of heat per unit of electricity under those conditions. So for steady, whole-house or open-plan heating — particularly with a heat pump — underfloor heating is generally cheaper to run than radiators, not more expensive. See running costs explained.
| Scenario | Running cost |
|---|---|
| Wet system, whole house, daily use | Usually lower than radiators |
| Wet system with a heat pump | Lowest |
| Electric mat, single bathroom, occasional | Economical |
| Electric system, large area, all day | Can be expensive |
When it can be expensive
The expensive scenario is an electric system asked to do a job it is not suited to — heating a large area for long hours every day. Because electricity costs more per unit than gas, the bill mounts quickly when an electric mat runs across a big floor. Electric UFH is economical for what it is designed for: a small bathroom or en-suite warmed for an hour or two. Using it as primary whole-house heating is where the “expensive” reputation comes from. See wet vs electric cost.
How to keep running costs down
Whichever system you have, a few things keep bills sensible: insulate under the system and around the room so heat is not wasted; use a programmable or smart thermostat suited to UFH’s slow response; zone the system so only the rooms in use are heated; and choose a floor finish that conducts heat well, such as tile or stone, or a rated engineered-wood or laminate — see floors and UFH. For a whole-house wet system, pairing it with a heat pump gives the lowest running cost of all. This is general information, not a forecast of your bills; ask your installer to estimate the running cost for your specific rooms and heat source. Underfloor heating should be fitted by a Gas Safe registered heating engineer (wet) or a NICEIC registered electrician (electric).
Compare underfloor heating quotes
Matching the system to the way you live is what keeps running costs low. Use our service to compare quotes from a Gas Safe heating engineer or NICEIC electrician in your area.
Frequently asked questions
Is underfloor heating cheaper than central heating?
A wet underfloor heating system is generally cheaper to run than radiators on the same central heating, because it heats a large surface at a lower flow temperature. Electric underfloor heating usually costs more per unit of heat, so it is best kept to small rooms. See UFH vs radiators.
Why do some people say underfloor heating is expensive?
Usually because they have an electric system heating a large area for long periods, where the higher cost per unit of electricity adds up. Electric UFH is economical in a small bathroom used occasionally; it becomes expensive as primary whole-house heating.
Does underfloor heating use a lot of electricity?
An electric system uses electricity directly, so it can if it heats a large area for long hours. A wet system mainly uses your boiler or heat pump, so its electricity use is limited to the pump and controls. The system type is what matters.
How can I reduce my underfloor heating bills?
Insulate well, use a thermostat suited to UFH’s slow response, zone the system to heat only rooms in use, choose a heat-conductive floor finish, and pair a wet system with a heat pump where practical. See running costs for more.
Sources & further reading
- Energy Saving Trust — underfloor heating running costs and efficiency
- Gas Safe Register — registered heating engineers for wet systems
- NICEIC — registered electricians for electric underfloor heating
- Manufacturer guidance — system design, controls and floor build-up
- GOV.UK / Building Regulations Approved Document L — efficiency standards
This is general information, not advice for your specific property and not a forecast of your bills. Running costs vary with energy prices, your home, insulation, heat source and use. Underfloor heating should be fitted by a Gas Safe registered heating engineer (wet) or a NICEIC registered electrician (electric). We are an independent information and introduction service, not an installer.