What could a new boiler cost you?

    Planning a replacement? Let’s look at installation and running costs together, then compare them with your current boiler. These are planning estimates, not a quote.

    A woman adjusting a radiator valve in her living room
    Illustrative household scene · AI-generated

    See also: How much does a new boiler cost in the UK?

    Figures reviewed June 2026 and updated monthly where appropriate. All results are estimates.

    Tell us about your home

    Bathrooms drive combi sizing (hot water). Home type and insulation drive heat demand.

    Optional product information · affiliate link
    Recommended for your homeAd
    tado Smart Thermostat Starter Kit
    Heating Controls

    tado Smart Thermostat Starter Kit

    Schedule, zone and remote-control your heating so it runs only when and where you need it.

    • Heat only when needed
    • Geofencing & schedules
    • Room-by-room control
    Shop on Amazon Typical benefit: Less heating of empty rooms

    Affiliate link — we may earn a small commission at no extra cost to you, which keeps PowerGuardian free and independent.

    How the Boiler Cost Calculator Works

    The calculator estimates the total cost of a new UK boiler in four stages. First it works out your home's annual heat demand from home type, bedrooms, bathrooms and insulation. It then applies your current boiler's age-based efficiency and your new boiler's rated efficiency to convert that heat demand into fuel used and fuel cost. Finally it adds the supply price, standard installation and any extras to give a lifetime figure and a simple payback against staying on your existing boiler.

    How Much Does a New Boiler Cost in the UK?

    Fully installed, most UK homeowners pay between £2,000 and £4,500 for a new boiler including labour. A basic combi swap in an easy-access location can come in around £2,000, while a premium combi with a powerflush, smart thermostat and a boiler relocation can reach £4,500 or more. System and regular boilers are typically £200–£400 more to install than a like-for-like combi swap.

    Combi, System or Regular?

    Combis heat water on demand and are cheapest to fit — ideal for smaller homes with one bathroom. System boilers pair with a hot water cylinder and cope better with two or more bathrooms running at once. Regular (heat-only) boilers suit older homes with existing feed-and-expansion tanks in the loft and are also common when planning a future move to a heat pump.

    How Much Could a New Boiler Save You?

    Replacing a 15-year-old boiler running at around 75% efficiency with a modern A-rated model at 93% can cut your annual gas use by roughly 20%. On a typical £900/year gas bill that's £150–£200 saved every year — often the biggest single running-cost win in the home.

    Frequently Asked Questions

    Stored on this device.