Underfloor Heating Running Costs UK 2026: From £0.55/Day — Worked Examples

Quick Answer: A 6 m² bathroom electric mat costs £0.55–£0.75/day to run (2 hrs/day at 27p/kWh). A 12 m² kitchen wet UFH on gas costs £1.60–£2.40/day (8 hrs/day at 6.9p/kWh). A 30 m² open-plan space with a heat pump runs at £3.20–£4.70/day. Full worked examples, efficiency tips, and calculator method below.

This page is the operating cost guide. If you need supply and installation prices first, start with the underfloor heating costs guide. If you are choosing electric or wet UFH, use the electric vs wet comparison. This article focuses on what the system costs after it is installed.

I’ve consulted with heating engineers and homeowners across the UK who’ve installed underfloor heating, and one question comes up constantly: “Will this bankrupt me?”

The honest answer? Underfloor heating can be cheaper to run than radiators—but only if it’s designed properly and you’re actually controlling it well. I’ve seen systems that seemed expensive at first glance turn out to be incredibly efficient, and others that cost a fortune because nobody thought about insulation or flow temperature tuning.

This 2026 guide cuts through the guesswork. I’ve used current UK price cap figures, realistic efficiency numbers from actual installations, and clear worked examples so you can budget accurately—and spot if something’s not right with your current system.

What you’ll actually pay in 2026

• Per m² (heated):
  • Electric mats: £0.23–£0.31 per hour at the 2026 cap (unit rates of ~27p/kWh; 170–230 W/m² output used intermittently).
  • Water (gas boiler): £0.06–£0.10 per hour (gas at ~6.9p/kWh; 75–90% system efficiency).
  • Water (heat pump assist): £0.04–£0.07 per hour (electricity at ~27p/kWh; COP 2.8–3.5 on low flow temperatures).
• Per room, typical winter schedule:
  • 6 m² bathroom electric mat (2 hours/day): £0.55–£0.75/day.
  • 12 m² kitchen wet UFH on gas (8 hours/day with setback): £1.60–£2.40/day.
  • 30 m² open-plan space with heat pump (10 hours/day, weather-compensated): £3.20–£4.70/day.

These figures assume good insulation and correct flow temperatures. If your system cycles on and off frequently or the floor covering insulates the pipes, expect the upper end of the ranges.

How to calculate your own running costs

If you’ve got a design sheet or know the basic specs of your system, you can work this out yourself. Trust me—once you see the formula, it’s pretty straightforward. Here’s what I use when I’m assessing a system for someone:

First, figure out how much heat you actually need

This is the foundation. You need either:

• For electric mats: the wattage per m² (usually printed on the product)
• For wet systems: your room’s heat loss (W) from a proper heat loss calculation, or ask your installer for the pipe output per circuit

Don’t guess this. A rough estimate now leads to nasty surprises later.

Next, account for real-world efficiency

Here’s where most people go wrong. Yes, electric heating is 100% efficient at the point of use, but your thermostat cycles on and off, which adds about 5–10% overhead. With gas boilers, you’re looking at 75–90% seasonal efficiency depending on the system and maintenance. Heat pumps are trickier—their COP (coefficient of performance) varies with the flow temperature you set. Run it at 45°C and you’ll see COP of 2.5–3.0. Run it at 30°C and it climbs to 3.5–4.0. Pick your actual design flow temperature and use that.

Then run the simple daily cost calculation

Multiply it out:

• Daily cost (£) = (Heat demand in kW ÷ efficiency) × your tariff (£/kWh) × hours it runs per day

For example: A 12 m² room with 70 W/m² design load = 0.84 kW demand. Gas boiler at 85% efficiency. Gas at 6.9p/kWh. Running 8 hours a day:

• (0.84 ÷ 0.85) × £0.069 × 8 = £0.55/day or about £16.50/month during winter.

Finally, account for your control strategy

This matters more than you’d think. A system that holds a steady low temperature consumes less energy than one cycling between off and full blast. Weather compensation (adjusting flow temperature based on outdoor temperature) cuts waste significantly. Night setback does help, but don’t drop the temperature too far—forcing a long reheat cycle in the morning wastes the savings.

If you do not have a heat loss calculation, use typical values: 60–80 W/m² for modern well-insulated rooms, 90–120 W/m² for older properties without upgrades. Always measure only the heated area, not the full room footprint.

2026 UK energy price benchmarks (price cap)

These are rounded averages for winter 2026–2027 Ofgem caps. Regional variance and supplier discounts apply; swap in your own rates for accuracy.

System-by-system comparison for 2026

Electric underfloor heating: the responsive option

Electric works best in bathrooms, small kitchens, loft conversions, or rooms you use occasionally. Why? Because it’s responsive—turn it on, and in 30–60 minutes you’ve got warmth. The trade-off is cost: you’re paying roughly 27p per kWh, which adds up if you’re running it all day.

But here’s what I’ve seen work really well: use electric as a targeted solution. A 6 m² bathroom mat running 2 hours a day costs less than £25/month, even in winter. Add a good thermostat with a floor sensor (28–29°C limit is key—you don’t want scalding floors), and presence detection on occasion-use rooms keeps the bill in check. Avoid the mistake of running an electric mat constantly “just in case.”

Water (wet) underfloor heating on a gas boiler

This is the traditional choice for whole-house heating, and it still makes sense if you’ve already got a condensing boiler. The economics work because gas is dirt cheap per kWh (6.9p) compared to electricity.

The critical thing I see installers get wrong? Flow temperature. Run gas UFH at 55–60°C and you’re not getting the efficiency benefits. Keep it below 45–50°C, and your boiler stays in condensing mode where it’s 10–15% more efficient. Smart zoning and weather compensation pay for themselves within a year by preventing the short-cycling and overshoot that waste energy. And actually balance your circuits—I’ve seen manifolds where one zone gets all the heat and others get nothing, forcing higher flow temperatures to compensate.

Water UFH with a heat pump: the efficient play

Heat pumps are the lowest-cost option if you’ve done the insulation properly and can run low flow temperatures (30–35°C). Under those conditions, COP climbs to 3.5–4.0, meaning you get 3.5 to 4 units of heat for every unit of electricity you consume.

The problem I see? People pair heat pumps with poor floor insulation or high-tog carpets, which forces higher flow temperatures. COP drops to 2.5–2.8, and suddenly it’s not the bargain it should be. Also avoid fiddling with the setpoint constantly—let weather compensation do its job. Pair a heat pump with smart controls and low-tog flooring, and you’ll have the cheapest heating in your street.

One bonus if you choose a reversible model: the same heat pump can run underfloor cooling in summer for pennies per day, since cooling EERs of 3 to 4.5 keep the delivered cost very low.

Room-by-room worked examples

Use these as guardrails; if your property has solid floors without insulation or drafty glazing, add 20–30% to the figures.

The real efficiency levers (and which ones matter most)

Not all efficiency tweaks are created equal. Some save you £5/month. Others save £50. Here’s what actually moves the dial based on what I’ve seen in real installations:

1. Insulation and floor buildup—this is the heavyweight

This is the single biggest factor. I’ve seen systems that looked expensive turn out to be cheap because someone invested in proper insulation, and vice versa. Thin insulation or high-tog carpets force you to run higher flow temperatures, which destroys efficiency across all system types.

Aim for <0.15 m²K/W resistance. Include perimeter insulation at screed edges (where heat leaks to the ground). If you’re using carpet, choose low-tog (<0.5 tog). The upfront cost of good insulation pays back within 2–3 winters and improves comfort dramatically.

2. Flow temperature—worth 10–15% of your running cost

Start wet systems at 30–35°C and only increase in 2°C steps if rooms won’t reach setpoint. This isn’t negotiable for heat pumps (they get expensive fast at high temps), but it also transforms gas boiler efficiency. Run a condensing boiler at 40°C instead of 55°C, and you’re looking at 10–15% less gas consumption. That’s real money.

3. Smart zoning and scheduling—40–50% savings potential

Don’t heat the study if nobody works there. Don’t run bathrooms at the same temperature as living areas. Group rooms by usage pattern. This is where weather compensation shines: it adjusts flow temperature based on outdoor weather, preventing the overshoot that wastes energy on mild days. I’ve seen this cut winter bills by £40–60/month in open-plan homes.

4. Smart thermostats and floor sensors—prevents costly mistakes

These aren’t just nice to have. A floor probe in a bathroom prevents overheating (you don’t want 32°C floors). Open-window detection stops heating when someone’s venting. Adaptive learning remembers your patterns and preheat times. They prevent the “boiler cycling on and off constantly” problem that kills efficiency.

5. Floor coverings—seems minor but adds up

Tiles and engineered wood are ideal. Vinyl is fine. But thick underlay or rugs can add 0.5 tog or more, which forces higher temperatures. I once consulted on a renovation where they’d put 2.5-tog wool rugs over UFH after installation—costs went up 20% compared to the design estimates. Swapping to low-tog rugs immediately cut £25/month off the bill.

6. Manifold balance and annual maintenance—the overlooked efficiency killer

Bleed air out of the circuits. Check manifold flow rates once a year. Ensure the pump’s proportional pressure valve is working (a pump set too high causes short cycling and noise). This stuff doesn’t cost much, but it prevents the constant on/off cycling that burns energy. One system I looked at had a pump set wrong—fixing it cut £15/month off the gas bill.

What to ask an installer before accepting a quote

Running costs are designed in before the floor goes down. Before accepting a UFH quote, ask:

• What heat loss figure has been used for each room?
• What flow temperature is the wet UFH designed around?
• What COP is assumed if a heat pump is involved?
• What insulation layer is included below the system?
• What floor covering and tog or thermal resistance has been assumed?
• How will each zone be controlled and balanced?

If an installer cannot answer those questions, the running-cost estimate is only a guess. For quote structure and red flags, use the underfloor heating quotation guide.

How UFH compares to radiators in 2026

• Comfort: UFH delivers even, low-level warmth and reduces convective draughts. Radiators create hot–cold spots and can feel stuffy at higher flow temperatures.
• Efficiency: With low flow temperatures (30–45°C), UFH keeps condensing boilers in condensing mode and maximises heat pump COP, typically cutting energy use by 10–25% versus well-sized radiators.
• Control and zoning: UFH allows granular zoning room by room; radiator TRVs often allow less precision unless paired with smart heads.
• When radiators still win: Quick warm-up in seldom-used rooms, heritage properties with limited floor build-up, or ultra-low budgets where capital cost trumps long-term running efficiency.

Maintenance and troubleshooting: catching problems before they cost you money

If your running costs are suspiciously high, check these things first:

Are rooms taking forever to reach temperature (>2 hours)? Is the manifold making noise like a coffee machine? Is the boiler cycling on and off constantly even on mild days? These are the red flags I see when something’s not right.

The quick self-checks anyone can do:

1. Check your thermostats, especially in bathrooms. If you’re running a floor probe, the limit should be 28–29°C. If the thermostat is reading air temperature instead, it’ll overshoot and waste energy.

2. Look at the manifold flow meters. If one circuit is getting 15 L/min and another’s only getting 5 L/min, they’re unbalanced. That cheaper circuit won’t heat properly, so your system works harder to compensate. Balancing takes 20 minutes and saves money monthly.

3. Check your setback temperatures. Night setback is good—drop it by 1–2°C to save energy. But if you’re dropping it by 5°C or shutting it off completely, you’re forcing a long reheat cycle in the morning that costs more than you saved overnight.

When you need to call your installer:

If circuits have persistent air in them (bleeding hasn’t fixed it), if you can’t get rooms above 18°C without running flow temperatures above 50°C (design issue or insulation problem), or if the boiler’s hunting (constantly cycling)—that’s beyond a DIY fix. There’s likely a deeper issue with circuit design, balancing, or the property’s insulation.

Check out our Underfloor Heating Manifold Guide for more detail on maintaining your system.

Frequently asked questions

Is underfloor heating worth it in 2026?

Honestly? Yes—but with caveats. If your home’s well-insulated and you’re pairing it with a heat pump or a modern condensing boiler, you’ll have comfortable heating that costs less than radiators. If you’re planning to install it in a draughty 1970s terrace with thin insulation and high ceilings, you might not see the savings. Do the heat loss calculation first. If your heating demand is reasonable, UFH is worth it.

How do I budget for seasonal changes?

Take the daily cost figures I’ve given you and multiply by the number of days you expect to be heating that month. Winter (Dec–Feb) typically runs 1.5–2× hotter than autumn and spring—factor that in. Interestingly, summer bathroom boosts on electric mats are usually pocket change, even for 2–3 months: less than £10/month usually. The big cost is winter heating. Budget accordingly.

Do I really need separate thermostats for each zone?

Ideally, yes—but it depends on your lifestyle. If you heat the entire house at the same temperature, one thermostat’s fine. But if you’ve got a study nobody uses, a guest bedroom, or different comfort preferences in different areas, separate controls (or a multi-zone smart system) pay for themselves within 1–2 years by not heating empty rooms. It’s also the only way to keep flow temperatures optimised across different zones.

Helpful resources and next steps

• Electric vs wet underfloor heating comparison
• Electric underfloor heating systems guide
• Wet underfloor heating design and installation
• Best flooring for underfloor heating
• Smart thermostat tips for UFH
• Common underfloor heating problems and fixes

Bookmark this guide and update the inputs with your latest tariff each quarter. If you are renovating or specifying a new system, use these calculations with your installer’s heat loss data to lock in low running costs for the life of the floor.