Are heat pump running costs cheaper than a gas boiler?

Yes, once the heat pump's efficiency (SCOP) is high enough. At 24p/kWh electricity and 6p/kWh gas, a heat pump with a SCOP of 4 produces heat for the same price as that gas boiler (6p per kWh of heat). Above a SCOP of 4 (e.g. the Vaillant aroTHERM plus at 5.03), the heat pump becomes cheaper to run than gas. Below a SCOP of 3, it's more expensive.

How much does it cost to run a heat pump per month in the UK?

A typical UK 3-bed home uses around 1,000–1,200 kWh of heat per winter month. At a SCOP of 4 and 24p/kWh electricity, that works out to roughly £60–£75 per month of heating — though real bills vary with outdoor temperature, thermostat setting and insulation. Across a full year, most UK heat pump homes spend £900–£1,250 on heating.

Why is electricity so much more expensive than gas per kWh?

UK electricity costs roughly 24p/kWh under the Ofgem price cap, while gas costs around 6p/kWh — about four times more. This is partly environmental levies and network costs loaded onto electricity. A heat pump overcomes this because it extracts 3–5 units of heat from the outside air for every 1 unit of electricity it uses, so the 'cost per unit of heat' drops to parity or below gas.

How much cheaper is an efficient heat pump than gas?

A heat pump with a SCOP of 5 (like the Vaillant aroTHERM plus at 5.03) produces heat at about 4.8p per kWh — roughly 25–30% cheaper than a gas boiler's effective ~6.7p per kWh (accounting for boiler efficiency). For a home using 12,000 kWh of heat a year, that's a saving of around £230 a year versus gas.

Do heat pumps use a lot of electricity?

A heat pump uses less total energy than a gas boiler because it's more efficient — but the energy it does use is electricity, which costs more per kWh. A typical 8kW heat pump draws about 2–3kW of electricity when running. On a discounted heat-pump electricity tariff (like Octopus Cosy or Agile), the running cost drops further and can beat gas by a wider margin.

Are heat pump running costs cheaper than a gas boiler?

Yes, once the heat pump's efficiency (SCOP) is high enough. At 24p/kWh electricity and 6p/kWh gas, a heat pump with a SCOP of 4 produces heat for the same price as that gas boiler (6p per kWh of heat). Above a SCOP of 4 (e.g. the Vaillant aroTHERM plus at 5.03), the heat pump becomes cheaper to run than gas. Below a SCOP of 3, it's more expensive.

How much does it cost to run a heat pump per month in the UK?

A typical UK 3-bed home uses around 1,000–1,200 kWh of heat per winter month. At a SCOP of 4 and 24p/kWh electricity, that works out to roughly £60–£75 per month of heating — though real bills vary with outdoor temperature, thermostat setting and insulation. Across a full year, most UK heat pump homes spend £900–£1,250 on heating.

Why is electricity so much more expensive than gas per kWh?

UK electricity costs roughly 24p/kWh under the Ofgem price cap, while gas costs around 6p/kWh — about four times more. This is partly environmental levies and network costs loaded onto electricity. A heat pump overcomes this because it extracts 3–5 units of heat from the outside air for every 1 unit of electricity it uses, so the 'cost per unit of heat' drops to parity or below gas.

How much cheaper is an efficient heat pump than gas?

A heat pump with a SCOP of 5 (like the Vaillant aroTHERM plus at 5.03) produces heat at about 4.8p per kWh — roughly 25–30% cheaper than a gas boiler's effective ~6.7p per kWh (accounting for boiler efficiency). For a home using 12,000 kWh of heat a year, that's a saving of around £230 a year versus gas.

Do heat pumps use a lot of electricity?

A heat pump uses less total energy than a gas boiler because it's more efficient — but the energy it does use is electricity, which costs more per kWh. A typical 8kW heat pump draws about 2–3kW of electricity when running. On a discounted heat-pump electricity tariff (like Octopus Cosy or Agile), the running cost drops further and can beat gas by a wider margin.

Heat Pump Running Costs UK 2026 — Real Numbers vs a Gas Boiler

Per month, per year, and per kWh of heat — at 24p/kWh electricity & 6p/kWh gas.

A heat pump is cheaper to run than a gas boiler as long as its SCOP is 4 or above. At the current Ofgem rates, a good heat pump (SCOP 4) produces heat at 6p per kWh — the same as a gas boiler after boiler losses — and a class-leading one (SCOP 5, like the Vaillant aroTHERM plus) at 4.8p per kWh, around 25–30% cheaper. For a typical UK 3-bed home that’s roughly £800–£1,250 a year in heating.

The Big 5: 1 of 5

Cost & Price — Cost per kWh of Heat, by SCOP

The only honest way to compare is cost per unit of heat delivered. A heat pump doesn’t turn 1 kWh of electricity into 1 kWh of heat — it multiplies it by its SCOP. Divide the electricity rate by the SCOP and you get the true cost of each kWh of warmth.

System	Cost per kWh of heat	Annual (12,000 kWh)	Vs gas
Gas boiler (90% efficient)	6.7p	£800	Baseline
SCOP 3.0 Low-end / poorly installed	8.0p	£960	More expensive
SCOP 3.5 Average air source	6.9p	£823	More expensive
SCOP 4.0 Good air source (Daikin, Samsung)	6.0p	£720	Cheaper
SCOP 4.5 High-efficiency (Octopus Cosy 6, Mitsubishi)	5.3p	£640	Cheaper
SCOP 5.0 Class-leading (Vaillant aroTHERM plus 5.03)	4.8p	£576	Cheaper

Annual figures assume 12,000 kWh of heat demand (typical 3-bed UK home). Electricity at 24p/kWh, gas at 6p/kWh, gas boiler ~90% efficiency. Excludes standing charges.

The Big 5: 2 of 5

Problems & Drawbacks — What Inflates the Bill

Problem 1: Bad weather and low SCOP undercut the savings

The SCOP is a seasonal average. On the coldest -5°C nights, an air source heat pump's efficiency drops towards 2–3, so the cost per kWh of heat spikes well above gas. If your installer sizes the unit poorly or your home is draughty, the real annual cost can sit at the expensive end of the range.

Problem 2: Economy-7 and standing charges blunt the gains

Most domestic tariffs charge a daily standing charge and one electricity rate. Unless you're on a heat-pump-specific tariff (Octopus Cosy, Agile, or a fixed off-peak rate), you can't fully exploit the heat pump's efficiency — some of the theoretical saving disappears in standing charges and the higher per-kWh rate.

Problem 3: Retrofitting radiators adds upfront cost

To run a heat pump efficiently at a low flow temperature (35–45°C), older homes often need larger radiators. That retrofit cost (£800–£3,000) is separate from the unit — and if you skip it, the pump runs at a higher flow, lower SCOP, and higher running cost.

The Big 5: 3 of 5

Versus & Comparisons — Heat Pump vs Gas, Head to Head

The chart below is the honest summary: at SCOP 4.0 the heat pump equals gas, at SCOP 4.5 it’s about 11% cheaper, and at SCOP 5.0 it’s roughly 28% cheaper. A heat pump on daytime-rate electricity still beats oil and LPG boilers comfortably, and crushes electric storage heaters.

The key number:

At a SCOP of 4, a heat pump produces each kWh of heat for 6.0p — meaning a typical 3-bed home costs roughly £720 a year to heat, versus about £800 for gas. On a discounted heat-pump tariff, the heat pump figure falls further and the gap widens in its favour.

Running costs by home size

Home	Annual heat demand	Heat pump (SCOP 4)	Gas boiler
1-2 bed flat	6,000 kWh	£360	£400
3-bed semi / terrace	12,000 kWh	£720	£800
4-5 bed detached	18,000 kWh	£1,080	£1,200

Heat pump figures assume a maintained SCOP of 4.0. Real heat demand varies with insulation, thermostat and climate — use these as planning figures, not quotes.

The Big 5: 4 of 5

Who the Running-Cost Maths Works Out For

Best value: replacing electric / oil / LPG heating

If you currently heat with electric storage heaters (£1,500–£2,200/yr) or oil/LPG (high per-kWh cost), a heat pump cuts your bill from day one even at a modest SCOP — because you’re beating an expensive baseline, not just gas.

Good: gas users on a heat-pump tariff

If your supplier offers a cheap heat-pump electricity rate (Octopus Cosy and Agile are the standouts), the cost per kWh of heat drops enough that a SCOP 3.5 unit still undercuts gas. Shop the tariff as carefully as the unit.

Marginal: gas users on standard rates, poorly installed

On a standard ~24p/kWh tariff with a poor SCOP (3 or below) and no tariff discount, the heat pump can cost more than gas. This is exactly why SCOP and installer quality matter more than any headline number.

The Big 5: 5 of 5

Verdict

Buy the most efficient heat pump you can afford and pair it with a heat-pump tariff. At SCOP 4.5–5, the running cost genuinely beats gas — and over a 15–20 year lifespan that annual saving compounds into real money. See the 10 best air source heat pumps by SCOP to find the most efficient models.

More on heat pumps

The 10 best heat pumps in the UK, compared →

Heat pump cost UK 2026 — full breakdown →

Air source vs ground source heat pump →

£7,500 Boiler Upgrade Scheme grant →

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Heat Pump Running Costs — Frequently Asked Questions

FAQ

Heat pump running cost FAQs

Are heat pump running costs cheaper than a gas boiler?: Yes, once the heat pump's efficiency (SCOP) is high enough. At 24p/kWh electricity and 6p/kWh gas, a heat pump with a SCOP of 4 produces heat for the same price as that gas boiler (6p per kWh of heat). Above a SCOP of 4 (e.g. the Vaillant aroTHERM plus at 5.03), the heat pump becomes cheaper to run than gas. Below a SCOP of 3, it's more expensive.
How much does it cost to run a heat pump per month in the UK?: A typical UK 3-bed home uses around 1,000–1,200 kWh of heat per winter month. At a SCOP of 4 and 24p/kWh electricity, that works out to roughly £60–£75 per month of heating — though real bills vary with outdoor temperature, thermostat setting and insulation. Across a full year, most UK heat pump homes spend £900–£1,250 on heating.
Why is electricity so much more expensive than gas per kWh?: UK electricity costs roughly 24p/kWh under the Ofgem price cap, while gas costs around 6p/kWh — about four times more. This is partly environmental levies and network costs loaded onto electricity. A heat pump overcomes this because it extracts 3–5 units of heat from the outside air for every 1 unit of electricity it uses, so the 'cost per unit of heat' drops to parity or below gas.
How much cheaper is an efficient heat pump than gas?: A heat pump with a SCOP of 5 (like the Vaillant aroTHERM plus at 5.03) produces heat at about 4.8p per kWh — roughly 25–30% cheaper than a gas boiler's effective ~6.7p per kWh (accounting for boiler efficiency). For a home using 12,000 kWh of heat a year, that's a saving of around £230 a year versus gas.
Do heat pumps use a lot of electricity?: A heat pump uses less total energy than a gas boiler because it's more efficient — but the energy it does use is electricity, which costs more per kWh. A typical 8kW heat pump draws about 2–3kW of electricity when running. On a discounted heat-pump electricity tariff (like Octopus Cosy or Agile), the running cost drops further and can beat gas by a wider margin.

Sources & cited data

Ofgem Electricity & Gas Price Cap Unit Rates — https://www.ofgem.gov.uk/energy-price-cap
Heat Pumps — Energy Saving Trust — https://energysavingtrust.org.uk/advice/heat-pumps/
MCS Heat Pump Efficiency & SCOP Certification — https://mcscertified.com/products-and-schemes/heat-pumps/
Boiler Upgrade Scheme — GOV.UK — https://www.gov.uk/apply-boiler-upgrade-scheme

SCOP figures are from MCS-certified product datasheets. Unit rates reflect the 2026 Ofgem price cap and are planning figures, not guaranteed tariffs.