Gas Boiler Running Costs: Is Gas Still Worth It?
Updated 28 March 2026
New gas boiler: £1,800-£4,000 installed. Annual running cost: £600-£1,200. But is gas still the right choice in 2026?
Quick answer
A new gas boiler costs £1,800-£4,000 installed. Annual running costs are £600-£1,200 depending on house size. Gas remains the cheapest heating fuel per unit in the UK at around 5.5p/kWh, but electricity costs are falling and heat pumps are becoming more competitive. The 2035 new-build ban affects new homes only, not replacements in existing properties.
Gas Boiler Running Costs by House Size
Based on current gas price of approximately 5.5p per kWh (April 2026 price cap). Assumes a modern condensing boiler rated 90%+ efficiency.
| Property Type | Annual Gas Use | Annual Cost | Monthly Cost |
|---|---|---|---|
| 1-bed flat | 8,000-10,000 kWh | £440-£550 | £37-£46 |
| 2-bed house/flat | 10,000-13,000 kWh | £550-£715 | £46-£60 |
| 3-bed semi (average home) | 13,000-16,500 kWh | £715-£910 | £60-£76 |
| 4-bed detached | 16,500-22,000 kWh | £910-£1,210 | £76-£101 |
| 5-bed detached | 22,000-30,000 kWh | £1,210-£1,650 | £101-£138 |
These figures cover heating and hot water. Actual costs vary by thermostat settings, insulation quality, and occupancy. Add the standing charge (around £100-£120/year) for your total gas bill.
Gas vs Heat Pump vs Electric: The 2026 Comparison
The heating system decision used to be simple. Now there are real alternatives worth considering, especially if you are replacing a boiler in a well-insulated home.
| Heating System | Install Cost | Annual Running (3-bed) | Best For |
|---|---|---|---|
| Gas boiler | £1,800-£4,000 | £715-£910 | Most homes, fast heat-up, familiar |
| Air source heat pump | £7,000-£15,000 | £600-£1,200 | Well-insulated homes, long-term savings |
| Ground source heat pump | £15,000-£35,000 | £500-£900 | Rural properties, large gardens |
| Electric storage heaters | £1,500-£4,000 | £1,200-£2,000 | No gas supply, flats, top-up heating |
| Hydrogen-ready boiler | £2,000-£4,500 | £715-£910 (on gas) | Future-proofing if hydrogen networks expand |
Heat pump grant
£7,500
Boiler Upgrade Scheme grant available toward an air source heat pump (2026)
Gas price per kWh
5.5p
vs 24p for electricity. Gas is still around 4x cheaper per unit
Heat pump break-even
10-15 yrs
Typical payback period after grant vs gas boiler replacement
The 2035 Gas Boiler Situation: What You Actually Need to Know
From 2035, new-build homes in England cannot be fitted with gas boilers as the primary heating system. This is part of the government's net zero targets.
What this does NOT mean: You cannot have your gas boiler replaced in an existing home after 2035. That is not the plan. Millions of existing homes will continue to run on gas for decades.
What it does mean: If you are buying a new-build from 2035 onward, it will likely have a heat pump or alternative heating. Resale values of older homes with gas boilers are unlikely to be affected in the short term.
Should you switch now? If your boiler is under 10 years old and your home is not well insulated, replacing it with a gas boiler makes financial sense. If you are doing a full renovation with high insulation and underfloor heating, a heat pump becomes much more attractive.
5 Ways to Cut Your Gas Bill Right Now
Lower your flow temperature
Most combi boilers are set to 80C by default. Dropping to 60C saves 6-8% on gas without reducing comfort. For older radiators, do not go below 60C.
Install a smart thermostat
Devices like Hive, Nest, or Tado learn your habits and avoid heating an empty house. Typical savings are £75-£150/year. Most cost £100-£200 to buy and fit.
Bleed your radiators
Air trapped in radiators means the boiler works harder. Bleeding them takes 10 minutes and costs nothing. If radiators are cold at the top, they need bleeding.
Add loft and cavity wall insulation
A quarter of heat is lost through the roof. Loft insulation costs £300-£500 and can save £150-£200/year. Cavity wall insulation can save a further £100-£150/year.
Get an annual boiler service
A service costs £60-£120 and keeps your boiler running at peak efficiency. A boiler that has not been serviced for 3 years can lose 10-15% efficiency, costing more than the service would have.
Frequently Asked Questions
How much does a new gas boiler cost to install?
A new gas boiler installed costs £1,800 to £4,000 for most homes. A budget combi boiler starts around £1,800 fitted. A mid-range model in a 3-bed home typically costs £2,200 to £2,800. Premium brands like Worcester Bosch or Viessmann cost £3,000 to £4,000 installed. The price includes removing the old boiler, fitting the new one, and testing.
How much does a gas boiler cost to run per year?
Annual running costs range from around £440 for a 1-bed flat to £1,650 or more for a large detached house. The UK average for a 3-bed semi is around £715 to £910 per year based on current gas prices of around 5.5p per kWh. This covers both heating and hot water.
Are gas boilers being banned in the UK?
From 2035, new-build homes cannot be fitted with gas boilers. Existing homes are not affected. You can still replace a gas boiler in your current home after 2035. The government wants to phase out gas heating gradually through incentives rather than forcing existing homeowners to switch.
Is a heat pump cheaper to run than a gas boiler?
It depends on your home and the heat pump's efficiency. Heat pumps use electricity at around 24p/kWh versus 5.5p for gas. A heat pump needs to be roughly 4x more efficient than gas to match on running costs at current prices. Well-insulated homes with underfloor heating or large radiators can achieve this. Draughty older homes with standard radiators often see higher bills with a heat pump.
Gas Boiler Cost Calculator
Estimate installation cost and annual running savings.
Installation Cost
£1,800 - £3,500
Supplied and fitted, 92% efficient
Annual Gas Bill Saving
£204/yr
Old (75%) vs new (92%)
Current Annual Gas Bill
£1104
At 75% efficiency, 6.9p/kWh
New Annual Gas Bill
£900
At 92% efficiency
Payback Period
~13 years
Energy savings cover installation cost
10-Year Total Saving
£2,040
In lower gas bills vs keeping old boiler
Based on Ofgem price cap of 6.9p/kWh. Actual bills vary by usage pattern and insulation.