New Boiler Costs UK: Installation Prices Explained (2026)

A new boiler is a fitted package, not just an appliance price. iHeat's average boiler installation order value was around £2,800 including VAT for fitting dates from September 2025 to August 2026. This rounded figure covers a mix of boiler installation jobs. It is a useful starting point for budgeting, not a fixed quote or a UK-wide average.

For a separate market reference, the Energy Saving Trust lists an average of £3,500 for replacing a G-rated gas boiler with an A-rated boiler and thermostatic radiator valves in Great Britain, checked on 14 September 2026. The scope differs from iHeat's mix of orders, so the two figures are not a like-for-like price comparison.

New boiler costs at a glance

Compare the total including VAT, installation and necessary materials. A low supply-only price does not tell you the finished cost. Equally, adding a separate labour allowance to an already installed price counts the same work twice.

How we calculated the iHeat average

We used iHeat's internal boiler installation order report for fitting dates from 1 September 2025 to 31 August 2026, reviewed on 14 September 2026. This covers several thousand installation orders and excludes the incomplete current month and forecast rows.

The benchmark is an order-weighted arithmetic mean: each month's average order value is weighted by its number of installation orders, rather than giving a quiet month the same weight as a busy month. We round the result to the nearest £100. The underlying monthly figures are themselves rounded, which does not change the published £2,800 benchmark.

The report uses recorded order values including VAT, with recorded package extras and price adjustments, rather than only payments already collected. It excludes cancelled, incomplete and proposal orders from the installation count. The figure describes installation orders by fitting date; it is not a claim that every account was fully paid at the reporting date.

This is iHeat customer data across the report's mix of boiler installations, not a combi-only or like-for-like-only average, a median, or an independently sampled UK market average. It does not describe what most customers paid within a particular range. Finance interest and future maintenance should be considered separately.

What will your boiler replacement involve?

The existing installation is often as important as the boiler you choose. Start by identifying the job below, then compare quotes for the same work. Use the scenario descriptions to check that competing quotes cover the same work.

If you do not know which system you have, use our boiler type guide. A straightforward replacement is often completed within a working day; conversions and relocations can take longer. Confirm the schedule and expected loss of heating and hot water with your installer.

Combi, system and conventional boiler costs

Combi boilers

A combi provides heating and hot water without a separate hot-water cylinder. That can save space and simplify a replacement where a suitable combi is already fitted. However, hot-water demand and the incoming water supply still matter, particularly if you want to use two showers at once.

Compare the exact model and output, its hot-water performance and the supplied controls. A higher-output combi may be selected for hot water, not because the radiators need that much heating power. Our combi boiler guide helps explain the model choices.

System boilers

A system boiler works with a separate hot-water cylinder. When reviewing its price, ask whether the installer is retaining your cylinder or supplying a new one. That single distinction can make two apparently similar quotations cover very different jobs.

Stored hot water can suit households with greater simultaneous demand. Cylinder capacity, recovery time, controls and water supply should be assessed together, rather than choosing from bedroom count alone.

Conventional or heat-only boilers

Replacing a heat-only boiler while keeping a serviceable cylinder and associated components can be a sensible option. Changing to a combi introduces additional work and changes how the home receives hot water.

Ask for a separate conversion price if you want both options. Read our vented and unvented cylinder comparison if a cylinder upgrade is part of the decision.

Oil and electric boilers

Do not apply a gas replacement benchmark automatically to an off-grid home. Oil installations may involve tank, fuel-line and flue work. Electric boilers can require an assessment of electrical supply capacity as well as the heating system. Running costs depend on fuel prices and heat demand, not just purchase price.

For context, Energy Saving Trust's boiler guide lists £3,200 for its oil replacement example in Northern Ireland. That is a specific regional and installation reference, not a nationwide oil-boiler quote. Obtain a quote for the actual fuel and system you intend to use.

Compare models and installation packages fairly

Brand-wide prices can hide a large difference between entry-level and premium models. Compare the exact boiler name, output, controls and warranty terms. If one quote offers a Worcester Bosch Greenstar 4000 and another an Ideal Logic Max Combi2, ask which output each includes and why it suits your home. See our Ideal versus Worcester Bosch comparison for published model differences.

A longer warranty can be valuable, but check registration, servicing and filter conditions. It does not automatically cover every component in your existing heating system. Also distinguish the manufacturer's appliance warranty from the installer's workmanship cover.

What is included, and what might cost extra?

Ask for the complete scope in writing. An item described as included is part of the overall package price; it is not something you should then add again when comparing totals.

• Boiler and labour: exact model, removal of the old appliance, installation, commissioning and required documentation.

• Flue and access: horizontal or vertical route, extensions, plume management where suitable, roof access and scaffolding if required. A new appliance needs a manufacturer-approved flue arrangement.

• Gas supply and condensate drainage: any pipe alterations identified during assessment. Pipe size is calculated for the installation; it is not a universal 15mm-to-22mm rule.

• Controls: the exact thermostat and any radiator valves. A wireless thermostat is not necessarily an internet-connected smart thermostat. App control, subscriptions and additional zones may be separate.

• System cleaning and protection: the specified cleaning method, inhibitor and filter. A chemical clean and a power flush are different services; a bottle of cleaning chemical is not the price of a complete cleaning job.

• Cylinder work: whether the existing cylinder is retained, replaced or removed, and the associated controls and pipework.

• Making good and disposal: who repairs holes, handles decoration and removes redundant equipment. Clarify any work left to another trade.

• VAT and payment: a VAT-inclusive cash total, deposit, balance and any separately selected finance agreement.

With iHeat, use the inclusions shown in your own fixed quote as the definitive package description. Check how any change in the agreed scope will be approved before work starts. Do not assume that an optional smart-control upgrade, cylinder or relocation is included merely because standard installation is included.

Worked example: comparing two boiler quotes

This is an illustrative calculation, not a customer installation or an iHeat offer. Quote A is £2,600 including VAT but excludes controls and required access work. If the written extras are £150 and £250, its comparable total is £3,000. Quote B is £2,900 including VAT with those same items included.

Quote B would be £100 lower for that scope, despite its higher headline price. Before deciding, also compare the model, warranty, cleaning method and workmanship cover. Only add an extra where it is genuinely required and excluded.

Use our boiler quote budget worksheet to organise your own figures. The new boiler installation page is the route to current packages and a property-specific quote.

Does a bigger home always need a more expensive boiler?

Not necessarily. Bedrooms are a rough description of a property, not a boiler-sizing calculation. An insulated four-bedroom home can have lower heating demand than a smaller, poorly insulated one. Baths, showers, occupants and simultaneous hot-water use affect the system choice too.

Ask the installer to assess heat loss and hot-water requirements. For combis, compare hot-water flow and minimum heating output as well as the headline maximum output. Keep serviceable radiators if they are suitable; replacing them should solve an identified problem rather than be an automatic part of every boiler job.

Repair or replace: which is better value?

Before buying a replacement, check whether the fault is covered by your warranty or existing cover. Compare a written repair price with the cost and benefits of a replacement. The boiler's condition, repeated faults, parts availability and suitability for your household matter alongside age.

A newer boiler may reduce fuel use, especially when replacing an inefficient older appliance, but savings are not guaranteed. Replacing one modern condensing boiler with another may offer much smaller energy savings than replacing an old non-condensing model.

For a savings estimate, use your annual gas consumption, the proportion used for heating and hot water, the old and new efficiencies, and your tariff. Label assumptions and include the cost of servicing. Avoid treating an exceptional detached-house saving as the amount every household will receive.

Can a grant help with a new boiler?

Funding depends on where you live, household eligibility and the technology being installed. A heat-pump grant is not a discount on a new gas boiler.

• England: the Warm Homes: Local Grant supports eligible households with energy-efficiency improvements and low-carbon heating. A council assessment determines the measures; do not assume it pays for a replacement gas boiler.

• England and Wales: the Boiler Upgrade Scheme supports eligible heat-pump and biomass installations. Check current technology and property rules before comparing an after-grant price with a boiler quote.

• Other support: check the official schemes for your nation and local authority. Eligibility and availability can change; our boiler grants guide is a starting point, with the scheme provider's current rules taking precedence.

Paying upfront or using boiler finance

Compare the VAT-inclusive cash price with the total payable under the finance agreement. Monthly payments alone do not show the full cost: check the deposit, term, APR, any fees and eligibility. Finance interest is separate from the installation-price benchmark above.

For available payment options, visit iHeat boiler finance. Choose an affordable package based on its full terms rather than assuming the lowest monthly payment is cheapest overall.

Get a quote you can compare with confidence

Start with the rounded £2,800 iHeat benchmark, then identify your installation scenario and the exact work needed. Have photos of the existing boiler, flue, controls and any cylinder ready for assessment. Explain any planned relocation or change in hot-water demand before accepting the price.

Keep a copy of the agreed model, inclusions, exclusions, total including VAT, installation schedule and warranty requirements. That gives you a much more useful comparison than choosing between broad price ranges alone.

Get a quote

Sources and review: iHeat internal installation-order reporting, fitting dates September 2025–August 2026; Energy Saving Trust boiler guidance; Warm Homes: Local Grant; Boiler Upgrade Scheme. External price references and scheme links checked 14 September 2026.