Estimate boiler replacement cost, VAT, potential fuel savings and simple payback.
Illustration only. Savings assume unchanged heat demand and fuel prices. Installation complexity, controls, property heat loss and occupant behaviour can materially change costs and savings.
How to use the Boiler Cost Calculator UK
Enter boiler and materials cost, labour, additional work and the VAT rate. To estimate fuel savings, also enter the current annual heating cost and the seasonal efficiencies of the old and new boilers.
How the estimate is calculated
| Result | Method |
|---|---|
| Pre-VAT project cost | Boiler and materials + labour + additional work |
| Installed cost | Pre-VAT cost + entered VAT |
| Estimated new fuel cost | Current fuel cost × old efficiency ÷ new efficiency |
| Simple payback | Installed cost ÷ estimated annual saving |
What a boiler quotation can include
A quotation may cover the appliance, flue, filters, controls, labour, removal of the old boiler, system cleaning, commissioning and certification. Relocation, difficult access, new pipework, cylinder work or radiator changes can increase the total.
Efficiency savings are an estimate
A more efficient boiler needs less fuel to deliver the same useful heat, but real savings depend on heat loss, controls, flow temperature, maintenance and household behaviour. This calculator holds heat demand and fuel price constant.
Building regulations and installation
GOV.UK states that installing a new or replacement heating system or boiler can fall under building-regulations requirements. Review the official home building-work guidance and use a suitably qualified installer.
Related calculators
Plan other exterior work with the Roofing Calculator. Estimate the property’s heating demand using the Heat Loss Calculator and review emitter requirements with the Radiator Size Calculator. Browse all tools on the United Kingdom Calculator homepage.
Frequently asked questions
What costs should I include for a boiler replacement?
Include the boiler, materials, labour, controls, removal, cleaning, commissioning and any additional pipework or building work.
Does this calculator include VAT?
Yes. Enter the applicable VAT percentage, or enter 0 when every cost already includes VAT.
How are annual fuel savings estimated?
The calculator compares old and new efficiency while assuming the same useful heat demand and fuel price.
Is simple payback a guaranteed result?
No. It is a planning estimate and does not account for future fuel-price changes, maintenance or finance costs.
Does a replacement boiler require approval?
Building-regulations requirements can apply. A registered competent installer may be able to self-certify the work.