New Boiler Installation Cost Calculator

How this calculator works

This calculator works in ranges rather than single figures, because real quotes, yields and tariffs genuinely vary that much. It starts from typical UK price, output and savings ranges drawn from published 2026 industry guides and official scheme documentation, then scales them by the quantities you enter and adjusts them for each choice you make below. The result is a low-to-high band that a realistic outcome is likely to fall within, not a promise of the figure you will achieve.

A new boiler costs to fully installed in the UK in 2026, with a straightforward combi swap at to and a market median of around based on thousands of real quotes. The price divides roughly evenly between the boiler unit itself and the Gas Safe labour, flue, filter and sundries, which is why two identical boilers can carry very different installed prices.

Job type

A like-for-like combi swap is the baseline job, one engineer-day with no pipework surprises, and the 2026 market median for exactly that job is around . System and heat-only replacements cost a little more for the extra components, converting a tanked system to a combi adds to for rerouting pipework and removing the cylinder and tanks, and relocating the boiler to a new room adds roughly to of labour, flue and pipe runs.

Boiler brand tier

Brand moves a quote by several hundred pounds either way: budget boilers do the same job with shorter warranties of around 2 to 5 years, mid-range brands balance price against 5 to 10 year cover, and the premium names, led by Worcester Bosch and Vaillant, cost 15 to 25 percent more for industry-leading reliability records and warranties up to 12 years. Over a 10 to 15 year boiler life, a long parts-and-labour warranty is worth real money, which is why premium brands hold their price.

Smart controls and filter package

Most 2026 installations include a magnetic system filter, which many manufacturers require for warranty validity, plus modern controls: a smart or programmable thermostat and thermostatic radiator valves. Together these typically add to and pay for themselves in fuel savings and warranty protection, and Building Regulations Boiler Plus rules require time and temperature control plus an efficiency measure on combi installations in any case.

Where you live

Heating labour is not priced uniformly across the UK, with published guides putting London and South East installation quotes roughly 15 to 25 percent above the national average. The hardware costs the same everywhere, so the difference sits in engineer day rates, access and parking.

What else affects the figures

The quote details matter more than the headline: a fair quote itemises the boiler model, warranty length, flue work, filter, controls, system flush and making good, and the cheapest number is only cheapest if it includes the same scope. Boilers last 10 to 15 years, so warranty length, 2 years at the budget end to 12 at the premium end, is a genuine part of the price comparison. Timing helps too, since emergency winter replacements command premium rates while planned autumn installations invite competition. Eligible low income households can qualify for a funded replacement under ECO4 where the existing boiler is old and inefficient, and anyone replacing a boiler in 2026 should at least price a heat pump alongside, since the Boiler Upgrade Scheme grant brings net heat pump costs into new-boiler territory.

Certification, planning and grid connection

Every gas boiler installation, repair or removal is legally restricted to Gas Safe registered engineers, and working on gas without registration is a criminal offence, so checking the engineer’s Gas Safe ID card and registration number is the non-negotiable first step. The installation is notifiable under Building Regulations, which registered installers self-certify, and Boiler Plus rules require time and temperature controls plus an efficiency measure on new combi installations. Flue positions and condensate drainage follow set standards worth confirming in the quote, an annual service protects both safety and the manufacturer warranty, and a carbon monoxide alarm near the boiler is cheap, sensible and in rented properties legally required.