Boiler Installation Cost Guide
A full breakdown of what boiler installation costs, scenario by scenario, and exactly what moves the price.
New boilers from £1,650 + VAT
- Gas Safe registered
- 12-month workmanship guarantee
- Clear written quotations
Boiler installation starts from £1,650 + VAT.
That is the genuine starting point for a straightforward replacement. What follows is a full explanation of the different installation scenarios and what each one involves, so you can work out roughly where your property is likely to sit before anyone visits.
Like-for-like replacement
The same boiler type, in the same position, where the existing pipework, gas supply and flue route are all suitable.
This is the lowest complexity scenario and usually the quickest installation, typically completed within a single working day. It is where the £1,650 + VAT starting figure applies.
What can push it above the starting price: a higher output boiler for a larger property, an undersized gas supply needing upgrade, or a system requiring a power flush.
Changing boiler type
Most commonly a regular boiler converted to a combi, though system to combi and combi to system also occur.
Additional work is required in every case. Converting to a combi means removing the hot water cylinder, decommissioning and removing the loft tanks, altering pipework throughout and changing the controls. Converting to a system boiler means installing and siting a cylinder.
Expect two to three days and a materially higher price than a straight swap. Making good plaster, tiling and decoration where components were removed is excluded unless specifically quoted.
Boiler relocation
Moving the boiler to a different wall or room. This requires new gas, water and condensate pipework to the new position, a new flue route, and capping or removal of the redundant runs.
This is the most variable scenario because it depends almost entirely on the building. A move from one side of a kitchen to the other is straightforward. A move from a kitchen to a loft is not.
Relocation often involves lifting floorboards, so allow for making good afterwards.
Heating system upgrades
Work carried out alongside the boiler installation, priced separately so you can see what each item adds:
- Power flush where system water is heavily contaminated
- Magnetic filter, included as standard on our installations
- Heating controls, such as a programmable thermostat and thermostatic radiator valves
- Radiator replacement where existing radiators are corroded or undersized
- Zoning for larger properties
Because the system is drained and being worked on anyway, these cost considerably less done at the same time than as a separate visit later.
Complex installations
Some properties simply take longer. Period buildings with restricted flue options, flats with lease or building constraints on flue termination and condensate discharge, loft installations, and properties where original pipework needs substantial upgrading all fall into this category.
Final pricing depends on the property and the existing heating system, which is precisely why we survey before quoting rather than guessing.
The key message
Every installation is assessed individually, with a clear written quotation provided before work begins.
We do not quote firm prices over the phone, and we do not add costs mid-job for anything we should have identified at survey. Where genuinely concealed problems come to light, we stop and agree the additional work with you before continuing.
Typical costs
| Type of work | Guide price | Notes |
|---|---|---|
| Like-for-like replacement | From £1,650 + VAT | Same type and position, suitable pipework and flue |
| Higher output boiler | Quoted after survey | Larger properties, more radiators or multiple bathrooms |
| Regular to combi conversion | Quoted after survey | Cylinder and loft tanks removed, pipework altered |
| Combi to system conversion | Quoted after survey | Cylinder supplied and sited, pipework altered |
| Boiler relocation | Quoted after survey | New gas, water, condensate and flue routes |
| Power flush | Quoted after survey | Heavily contaminated system water |
| Heating controls upgrade | Quoted after survey | Programmer, thermostat and TRVs |
| Gas supply upgrade | Quoted after survey | Where existing pipe is undersized for the new appliance |
Guide prices only. Every installation is assessed individually and a clear written quotation is provided before any work begins.
Frequently asked questions
How much does boiler installation cost in the UK?
Straightforward replacements commonly start in the region of £1,650. Our installations start from £1,650 + VAT, with conversions, relocations and complex installations quoted after survey.
What is the cheapest boiler installation scenario?
A like-for-like replacement in the same position with suitable existing pipework and flue. It involves the least labour and materials.
Why does a combi conversion cost more?
Because there is significantly more work: removing the cylinder and loft tanks, altering pipework throughout, changing controls, and capping redundant runs. It typically takes two to three days rather than one.
Is making good included in the price?
No. Plastering, tiling, decorating and cosmetic repairs are excluded unless specifically written into your quotation.
Can the price change after work starts?
Only where genuinely unforeseen problems are uncovered, such as concealed corrosion or non-compliant previous workmanship. We discuss any additional work with you before proceeding.