Air Source Heat Pump vs Gas Boiler: Running Costs Compared

The Big Question: Is a Heat Pump Cheaper to Run Than Gas?

At current 2026 energy prices (Ofgem: electricity 24.5p/kWh, gas 7.4p/kWh), a heat pump running at a seasonal COP of 3.5 costs approximately 7.0p per kWh of useful heat — compared to 8.0p for a gas boiler at 92% efficiency. For an average home, that is a typical saving of £100–£300 per year on energy bills, based on Energy Saving Trust data, before accounting for the elimination of the gas standing charge.

The answer depends on the numbers. Not marketing claims, not manufacturer brochures — actual energy prices, real-world efficiency, and honest maths. In this guide, we compare the running costs of an air source heat pump against a gas boiler using 2026 UK energy prices, explain the science behind heat pump efficiency, and project costs over 10 years to show you the full financial picture.

Understanding Efficiency: COP vs Boiler Efficiency

Before diving into the numbers, it helps to understand why heat pumps can be cheaper to run despite electricity being more expensive per unit than gas.

Gas boiler efficiency

A modern condensing gas boiler operates at around 90–92% efficiency. That means for every £1 of gas you burn, you get roughly 91p worth of heat. The rest is lost through the flue.

Heat pump efficiency (COP)

A heat pump does not burn fuel. Instead, it extracts heat from the outdoor air and concentrates it using a refrigeration cycle — the same principle as a fridge, but in reverse. The measure of efficiency is the Coefficient of Performance (COP).

A well-installed air source heat pump achieves a seasonal average COP of 3.0 to 4.0. That means for every 1 kWh of electricity it uses, it produces 3 to 4 kWh of heat. In percentage terms, that is 300–400% efficiency.

This is the key advantage. Even though electricity costs more per unit than gas, the heat pump stretches each unit three to four times further.

2026 Running Cost Comparison

Let us use real numbers. The figures below are based on Ofgem’s price cap rates for Q2 2026:

At these prices, the heat pump is approximately 14% cheaper to run for space heating (Energy Saving Trust).

Adding hot water

Most households also use their heating system for domestic hot water. A typical UK household uses around 3,000 kWh per year for hot water.

Total annual heating and hot water:

The Standing Charge Factor

There is an additional saving that many comparison articles overlook. When you switch from gas to a heat pump, you can disconnect your gas supply entirely, eliminating the gas standing charge.

In 2026, the gas standing charge is approximately 32p per day, which adds up to £117 per year (Ofgem) — money you pay whether you use any gas or not.

Adding this to your running cost savings:

• Heating and hot water saving: £170
• Gas standing charge eliminated: £117
• Total annual saving: £287

That changes the picture considerably.

What Happens When Energy Prices Change?

Running cost comparisons are snapshots in time. What matters for a long-term investment like a heat pump is the trend.

The gas price outlook

Gas prices in the UK have been volatile since 2021. While prices have retreated from their 2022 peaks, the UK remains heavily dependent on imported gas, and prices are influenced by global markets, geopolitical events, and declining North Sea production. Most energy analysts expect gas prices to remain volatile and trend upwards over the coming decade.

The electricity price outlook

Electricity prices are also subject to change, but the UK is rapidly expanding its renewable energy capacity. As more wind and solar come online, the underlying cost of electricity generation is falling. The government has also committed to decoupling electricity prices from gas prices, which should reduce the impact of gas market volatility on electricity bills.

The ratio that matters

The critical number is the electricity-to-gas price ratio. Currently, electricity is roughly 3.3 times more expensive than gas per kWh. A heat pump with a COP of 3.5 breaks even at a ratio of 3.5:1, and saves money at anything below that.

If the ratio narrows — which most forecasts suggest it will — heat pumps become progressively cheaper to run relative to gas.

10-Year Cost Projection

Let us project total energy bills over 10 years under three scenarios:

Scenario 1: Prices stay flat

10-year saving with heat pump: £2,870

(Gas total includes the standing charge of £117/year)

Scenario 2: Gas rises 5% per year, electricity rises 3% per year

10-year saving with heat pump: £4,810

Scenario 3: Gas rises 3% per year, electricity falls 1% per year (renewable transition)

10-year saving with heat pump: £5,380

Under every realistic scenario, the heat pump comes out ahead over 10 years. The question is not whether it saves money, but how much.

When Does a Gas Boiler Still Win?

Honesty matters. There are situations where a gas boiler may still be cheaper in the short term:

Very poorly insulated homes

If your home has severe heat loss — no loft insulation, single glazing, uninsulated solid walls — a heat pump will need to work harder and may operate at a lower COP. In these cases, it makes sense to improve insulation first. A reputable installer like Electromatic M&E Ltd will always advise on this during the home survey.

Undersized or poorly installed heat pumps

A heat pump that is too small for the property, or one installed by an inexperienced company, will not achieve the COP figures used in our calculations. This is why working under MCS certification and proper system design matter so much.

Very low gas tariffs

If you are on an exceptionally cheap fixed gas tariff, the maths may not stack up until that tariff ends. But fixed tariffs do end, and the trend is clear.

Maintenance Costs: Another Win for Heat Pumps

Gas boilers require an annual service (typically £80–£120) and a gas safety certificate. They also have a shorter lifespan of 12–15 years and are prone to breakdowns as they age.

Heat pumps require less frequent servicing — typically every 2–3 years — and have a lifespan of 20–25 years. There is no combustion, no risk of carbon monoxide, and fewer moving parts to wear out.

Over the lifetime of the system, maintenance savings add another £1,000–£2,000 to the heat pump’s financial advantage.

The Combined Case: Heat Pump Plus Solar

If you really want to slash running costs, consider pairing your heat pump with rooftop solar panels. A typical 4 kWp solar system generates around 3,400 kWh per year in southern England — enough to power your heat pump for a significant portion of the year at zero marginal cost.

Related reading: Solar Panels and Heat Pumps: The Perfect Combination

How Electromatic Can Help

Electromatic M&E Ltd offers free home surveys across London and Surrey (TW, KT, SW postcodes). We handle BUS Grant applications, install ASHP and solar PV from a single contractor, and deliver within 2–4 weeks of survey confirmation. All work is carried out under MCS certification via our accredited umbrella partner. We will show you exactly what your energy bills would look like with a heat pump, based on your home’s actual heat loss and energy use.

Book your free home survey →

Call us: 07718 059 284 | Email: admin@electromatic.uk

Frequently Asked Questions

Are heat pumps cheaper to run than gas boilers?

At 2026 Ofgem price cap rates (electricity 24.5p/kWh, gas 7.4p/kWh), a heat pump at COP 3.5 costs approximately 7.0p per kWh of useful heat — roughly 12% less than a gas boiler’s 8.0p. Savings increase significantly when you add a smart electricity tariff or solar panels. Typical annual savings are £100–£300 on energy bills (Energy Saving Trust), plus £117/year in gas standing charges if you disconnect.

How does a heat pump’s COP compare to a gas boiler?

A modern condensing gas boiler operates at approximately 92% efficiency — so 0.92 kWh of heat for every 1 kWh of gas. An air source heat pump achieves a seasonal COP of 3.0–4.0, meaning 3–4 kWh of heat per 1 kWh of electricity. Even though electricity costs more per unit, the heat pump delivers so much more heat per unit that the effective cost of warmth is lower.

What energy prices were used in this comparison?

All figures use Ofgem’s Q2 2026 price cap rates: electricity at 24.5p/kWh and gas at 7.4p/kWh. Standing charges are approximately 32p/day for gas and 61.6p/day for electricity.

What is the payback period on a heat pump?

The payback depends on your installation cost, the BUS Grant (subject to eligibility), and your annual savings. For a homeowner replacing an ageing boiler, the net additional cost after the £7,500 grant is often just £1,000–£2,500, which can pay back in 4–10 years through reduced energy bills and avoided maintenance. Read our full cost guide: How Much Does a Heat Pump Cost in 2026?

Will the cost advantage of heat pumps grow over time?

Almost certainly. Gas prices are expected to remain elevated due to declining UK production and global LNG competition. Meanwhile, UK electricity prices are forecast to fall as more renewable generation comes online. The electricity-to-gas ratio is narrowing, which directly improves heat pump economics year on year.

The information in this article is for general guidance only and does not constitute financial, legal, or technical advice. Energy savings estimates are based on typical UK household data from the Energy Saving Trust and Ofgem (April 2026 price cap). Actual savings depend on your property type, insulation levels, energy usage patterns, and electricity tariff. The Boiler Upgrade Scheme (BUS) grant of £7,500 is subject to eligibility criteria set by Ofgem — not all properties qualify. Electromatic M&E Ltd operates under MCS certification via an accredited umbrella partner. All installations comply with Building Regulations Part L and MCS standards. E&OE.

Written by Electromatic M&E Ltd — ASHP & Solar installer, London & Surrey (electromatic.uk)

Last updated: April 2026 | Electromatic M&E Ltd, Company No. 13837345