A new gas boiler costs £1,800 to £4,500 fitted in the UK.
Three types, three prices. Pick the right one with the calculator below, then see what it will actually cost to run at the Q2 2026 Ofgem cap.
Single unit, no cylinder, no tank. Hot water on demand. Cheapest to install for 1 to 3-bed homes with one bathroom.
- Heats water on demand
- No tanks or cylinders
- Best for 1 bath, 1 to 3 bed
Heated water stored in a cylinder. Handles multiple bathrooms running at once. Ideal for 3 to 5-bed homes.
- Stores hot water in cylinder
- Two showers at once, no drop
- Best for 2+ baths, 3 to 5 bed
Cylinder plus a cold-water tank in the loft. Suits older properties and low mains pressure. Long lifespan.
- Cylinder and loft tank
- Works with low mains pressure
- Best for older or large homes
Get a real range in 30 seconds
1 to 3-bed, 1 bathroom. Recommended output for your size: 28-32 kW.
Based on indicative quotes for the inputs above. Always get three Gas Safe quotes.
Running cost uses Ofgem Q2 2026 cap (5.74p/kWh gas, 29.09p/day standing charge) and typical UK gas use for the chosen property. Your bill depends on insulation, thermostat habits and hot water demand.
Full cost breakdown by type and tier
| Type and tier | Boiler supply | Labour and parts | Total installed | Best fit |
|---|---|---|---|---|
| Combi (budget) | £600 to £900 | £1,000 to £1,400 | £1,800 to £2,300 | Like-for-like swap, 1 to 2-bed |
| Combi (mid-range) | £900 to £1,400 | £1,100 to £1,800 | £2,200 to £3,100 | 3-bed semi, 1 bathroom |
| Combi (premium) | £1,400 to £1,900 | £1,200 to £1,900 | £2,800 to £3,500 | Long-warranty premium model |
| System (budget) | £800 to £1,200 | £1,100 to £1,800 | £2,000 to £3,000 | 3-bed, existing cylinder reused |
| System (mid-range) | £1,200 to £1,700 | £1,300 to £2,200 | £2,700 to £3,800 | 4-bed semi or detached |
| System (premium) | £1,700 to £2,200 | £1,400 to £2,400 | £3,500 to £4,500 | 5-bed, two bathrooms or more |
| Conventional (budget) | £700 to £1,100 | £1,000 to £1,700 | £1,700 to £2,700 | Older home, traditional system |
| Conventional (mid) | £1,100 to £1,500 | £1,300 to £2,200 | £2,400 to £3,500 | Higher demand, larger property |
| Conventional (premium) | £1,500 to £1,900 | £1,400 to £2,500 | £3,000 to £4,000 | Heritage home, low mains pressure |
Ranges based on indicative quotes from UK installer comparison platforms (April 2026). Always obtain three quotes from Gas Safe registered engineers before any work begins.
Six things that move the price
Boiler type
Combi is cheapest to install. System suits multiple bathrooms. Conventional fits older systems.
Brand tier
Budget brands like Ideal start near £500 supply. Premium models reach £1,800 or more on supply alone.
Property size
Output rating (kW) climbs with property size. Larger homes need bigger units and longer pipework.
Installation complexity
Like-for-like swap is fastest. Relocation adds £250 plus. Full conversion adds £600 to £1,500.
Region
London labour runs 25 to 35% above the North East. The estimator above uses regional multipliers.
Extras
Powerflush £300 to £500. Magnetic filter £100 to £150. TRVs £150 to £300. Smart thermostat £150 to £250.
What your home should pay
Recommended boiler output and a typical UK installed range, paired with the running cost for that property at the Q2 2026 Ofgem cap.
| Property | Boiler output | Typical installed | Annual gas (heat + DHW) |
|---|---|---|---|
| 1-bed flat | 24 kW | £1,800 to £2,400 | £420 to £540 |
| 2-bed flat or terrace | 24 to 28 kW | £2,000 to £2,800 | £540 to £660 |
| 3-bed semi | 28 to 32 kW | £2,300 to £3,300 | £700 to £870 |
| 4-bed detached | 32 to 35 kW | £2,800 to £3,900 | £950 to £1,150 |
| 5+ bed detached | 35 to 42 kW | £3,500 to £4,500 | £1,250 to £1,520 |
Boiler efficiency ladder
ErP / SAP bands- A92%+ efficient: best of breed ← your boiler
- B89 to 91%: most modern condensing
- C84 to 88%: older condensing
- D78 to 83%: early condensing
- E72 to 77%: pre-2005 non-condensing
- F65 to 71%: old back boiler era
- GUnder 65%: wasting money daily
Every new gas boiler sold in the UK since 2005 must be condensing and at least band A. Older homes often still run band D, E or worse: the ladder above shows what each step costs you.
Where 2026 prices sit
per kWh, Q2 2026 average
per day, paid even at zero use
per kWh, used in heat-pump comparison
Boiler hardware prices have stabilised in 2026 after several years of supply-chain pressure. The bigger swing is labour: Gas Safe engineer day rates rose roughly 6% in the year to April 2026. Booking outside the autumn rush (September to December) typically saves 8 to 12% on installation.
Pick your next question
Boiler types
ChooseCombi vs system vs conventional with a clear decision framework.
OpenRunning costs
BillsWhat gas heating costs per year by property at the Q2 2026 cap.
Openvs Heat pump
Compare10-year and 15-year total cost of ownership, honest maths.
Open2035 ban
PolicyWhat the Future Homes Standard means for existing homes.
OpenBest brands
BrandsWorcester Bosch, Vaillant, Ideal, Baxi, Viessmann compared.
OpenServicing
MaintainAnnual service vs boiler cover. £80 to £120 versus £10 to £25 a month.
OpenRegional costs
RegionLondon to Scotland: actual installation prices by region.
OpenGrants and finance
PayECO4, BUS, finance and boiler-on-prescription explained.
OpenSave money
SaveTen ways to cut gas bills, with quantified annual savings.
OpenInstallation
ProcessDay-by-day timeline and every itemised hidden cost.
OpenGas boiler cost FAQ
How much does a new gas boiler cost in the UK in 2026?
A new gas boiler typically costs £1,800 to £4,500 fully installed. A combi runs £1,800 to £3,500, a system boiler £2,000 to £4,500, and a conventional £1,700 to £4,000. The supply price is roughly half: the rest is labour, parts and any extras like a powerflush or new flue.What type of boiler do I need?
For a 1 to 3-bed home with one bathroom, a combi is almost always the right answer. From three bedrooms with two or more bathrooms, a system boiler keeps showers running together without dropping pressure. A conventional boiler suits older homes, low mains pressure, or when the existing tanks and cylinder are still serviceable. Our boiler types page walks through the decision in detail.Are gas boilers being banned in 2035?
Only in new-build homes. The Future Homes Standard removes new gas boilers from new construction, not from your existing house. You can still buy, fit and service a gas boiler for decades. Read the full explainer on the 2035 ban page.How much does it cost to run a gas boiler per year?
At the Q2 2026 Ofgem cap (5.74p/kWh plus 29.09p/day standing charge), a 3-bed semi using 12,000 kWh of gas costs about £750 to £870 per year for heating and hot water. A 4-bed detached on 17,000 kWh costs £950 to £1,150. Full breakdown by property on the running costs page.Is a heat pump cheaper than a gas boiler?
Cheaper to run, more expensive to install. Over 10 years a gas boiler usually wins on total cost. By 15 years a heat pump pulls ahead, especially with the £7,500 Boiler Upgrade Scheme grant. We work the numbers on the gas vs heat pump page.How long does a gas boiler last?
A combi: 10 to 15 years. A system boiler: 12 to 15. A conventional: 15 to 20. Annual servicing by a Gas Safe engineer is the single biggest factor in reaching the high end of each range.
More questions on the full FAQ page, with policy, type, brand and grant questions answered.
Going deeper on a combi specifically? See the dedicated guide at CombiBoilerCost.com. Already committed to a replacement? Walk through the process at BoilerReplacementCost.com.