New Boiler Cost UK: What to Budget and Compare in 2026
For a starting budget, Energy Saving Trust currently gives £3,500 as a typical Great Britain cost to replace a G-rated gas boiler with an A-rated boiler and thermostatic radiator valves. That is a national example, checked on 9 September 2026, rather than a fixed Leicester quote. Your final cost depends on the proposed system and installation work.
By Plumber Leicester Pro editorial team · Checked . General guidance; use your appliance instructions for your model.
In this guide
The Energy Saving Trust cost guide provides the scope behind that figure. Use it to start a conversation, then compare itemised quotes for your own home. A boiler-only price and a fully installed price are different purchases.
What changes the installed price?
| Part of the job | What to have written down |
|---|---|
| Boiler and controls | Exact model and output; compatible room controls; any radiator controls included. |
| Keeping or changing the system | A straightforward replacement, relocation or switch between combi and cylinder-based hot water. |
| Pipework and access | Gas-supply suitability, heating connections, condensate route, flue access and any scaffolding. |
| Cleaning and protection | The cleaning method justified for your system, filter provision and water treatment. |
| Finishing and removal | Waste removal, patching walls, boxing in, electrical work and any excluded decoration. |
| Handover | Commissioning documents, relevant notification, guarantee registration and explanation of controls. |
Do not assume a particular gas-pipe diameter is right for every installation. Ask the installer to assess the supply and describe any changes. A heating survey should also consider heat loss, existing radiators, water supply and how many hot outlets you want to use at once.
Combi replacement, relocation or a different system?
Keeping a suitable boiler in the same position usually involves a different scope from moving it or removing a cylinder. Ask for the reason behind a proposed system change and the work it adds. See combi versus system boilers before choosing based on the boiler price alone.
Two quotes can look very different because one includes a cylinder, controls or access work that the other leaves out. If the proposed boiler model differs, compare its suitability, guarantee conditions and total installed cost. A brand name alone does not establish the right choice for your home.
Does a new boiler always need a power flush?
Ask how the existing system will be assessed and cleaned to meet the new boiler’s installation requirements. System age alone does not establish that power flushing is the correct method. Fernox’s cleaning guidance explains why cleaning and subsequent protection matter; the installer should choose a method suitable for the installation. Read what to ask about power flushing before accepting a separate charge.
Check the guarantee and payment terms
Ask who provides the guarantee, how long it lasts, what it covers, how it is registered and what servicing records are required. Extended cover can depend on the model, installer and additional products. Worcester Bosch’s guarantee terms illustrate why a headline number of years is not enough.
Get the supplier’s deposit, payment stages, cancellation terms and invoice details in writing. This website does not publish a finance offer or a universal deposit policy. Compare the total payable if a supplier offers credit; a low monthly payment does not show the total cost. An estimate should state what could change after inspection.
Can a grant help?
The Boiler Upgrade Scheme supports eligible low-carbon heating in England and Wales, rather than an ordinary like-for-like gas-boiler replacement. Check the current technology-specific grant and eligibility on GOV.UK before budgeting. Do not subtract a heat-pump grant from a gas-boiler quote.
For an alternative heating proposal, compare the whole installed system: any cylinder, radiator changes, electrical work and expected running costs. Ask how those costs were calculated for your home. A grant is useful only if the property, system and application qualify.
How to compare three quotes
- Give each installer the same property information and desired work. Include the existing model, fuel type, hot-water cylinder and number of bathrooms.
- Ask for one total showing the VAT position, inclusions and exclusions. Keep provisional sums separate from confirmed work.
- Check the installer’s identity and relevant Gas Safe registration before gas work. Agree who takes payment and handles a complaint.
- Compare installation timing, aftercare and guarantee conditions as well as price. Ask what happens if extra work is found.
Repair or replace?
Age alone does not decide the answer. Compare a diagnosed repair quote with a replacement quote, the boiler’s condition, parts availability and your future heating plans. Our repair-or-replace guide helps you gather that information without assuming a fixed payback period.
Want a boiler quote for your Leicester home?
Provide your postcode, existing boiler model and whether you want a replacement in the same position or a different system. The installer will confirm the survey and quote arrangements.
Call 0116 488 6858 Request a boiler quote
24/7 enquiries. The supplier confirms availability, the work and charges before you agree to a booking.
