Heat Pump vs Gas Boiler: Running Costs Compared for 2026

The Basics: How Each System Works

A gas boiler burns natural gas to heat water, which circulates through radiators and provides hot water. It is a simple, well-understood technology that has heated UK homes for decades.

An air source heat pump works differently — it extracts heat from the outside air (even in cold weather) and concentrates it to heat your home. For every 1 kWh of electricity it uses, a modern heat pump produces 3–4 kWh of heat. This is why heat pumps are described as being 300–400% efficient.

We install both systems and have no commercial bias towards either. This comparison is based on real-world data from our installations across Cornwall.

Installation Costs Compared

A new gas boiler installation typically costs £2,500–£4,500 depending on the boiler model and complexity of the work.

An air source heat pump installation costs £8,000–£14,000 before the grant. After the £7,500 BUS grant, the out-of-pocket cost is £2,500–£6,500 — much closer to a boiler replacement. See our detailed heat pump cost breakdown.

Annual Running Costs

Based on a typical 3-bedroom semi-detached home in Cornwall:

• Gas boiler: £800–£1,200 per year (gas price ~7p/kWh, boiler 90% efficient)
• Air source heat pump: £500–£900 per year (electricity ~24p/kWh, COP of 3.2–3.8)
• Heat pump + solar panels: £300–£600 per year (solar offsets daytime electricity use)

The heat pump advantage grows significantly when paired with solar panels and battery storage, as you generate free electricity to run it.

Total Cost of Ownership Over 20 Years

Over a 20-year period (the typical lifespan of a heat pump), the total cost of ownership including installation, maintenance, and energy tells a clearer story:

• Gas boiler (replacing once at year 12): £28,000–£38,000
• Heat pump (with BUS grant): £16,000–£26,000
• Heat pump + solar: £20,000–£30,000 including solar cost, but with electricity bill savings across the board

Gas boilers last 12–15 years on average, so you will likely need two boilers in the same period a single heat pump covers. Heat pumps require less maintenance — typically an annual service costing £100–£150 versus £80–£120 for a boiler, but without the more expensive breakdowns gas boilers are prone to as they age.

When a Heat Pump Makes More Sense

• You are on oil or LPG (higher fuel costs mean faster payback)
• You are eligible for the £7,500 BUS grant
• You already have or plan to install solar panels
• You want to future-proof against rising gas prices and the boiler phase-out
• You are building an extension or renovating (ideal time to install underfloor heating too)

When a Boiler Is the Better Choice

• Your boiler has failed and you need emergency replacement within days
• You have very limited outdoor space for the heat pump unit
• Your budget cannot stretch beyond a basic boiler swap right now
• You plan to move within 2–3 years (though a heat pump will add property value)

We offer gas and LPG boiler installations from Worcester Bosch and Vaillant, so if a boiler is the right choice for your situation, we can help with that too.

Our Recommendation

For most homeowners who qualify for the BUS grant, a heat pump is the better long-term investment. The grant has levelled the upfront cost difference, and running costs are lower — especially when combined with solar.

The best first step is a free home survey where we assess both options for your specific property and give you honest advice on which makes more sense. We serve St Austell, Bodmin, Truro, and all areas across Cornwall.