Boiler prices: the unit versus the full installed bill
Searching for boiler prices? Here is what the boiler itself costs, what drives the installed total, and how to read a quote line by line.
Boiler prices in the UK typically land at £2,800 fully installed for a mid-range job, with a usual range of £2,200 – £3,650. The boiler you see priced in a shop is only part of that figure, which is why installed quotes look so much higher.
Why shop prices and quotes differ
A price tag on a boiler covers the appliance and little else. A quote covers a working heating system that has been fitted, commissioned and signed off. We build our figures from labour hours × local rates plus materials, then check them against market prices and real quotes. For a boiler job, the bill breaks down into these parts:
- The unit. The boiler itself, with its manufacturer's warranty. This is the line people compare online.
- Flue. A standard flue kit in the same position is cheap. A new vertical flue through the roof, or moving the boiler to another room, adds materials and several hours of labour.
- Controls. A programmable room thermostat is the baseline. A smart thermostat with an app costs more.
- System clean. Either a chemical clean or a full power flush, so old sludge does not damage the new boiler.
- Labour. Draining down, removing the old boiler, fitting, pipework, gas connection, commissioning and certification.
- Extras. Filters, fittings, waste disposal and VAT, which is included in our figures at 20%.
The unit is often well under half of the total. Labour, the flue and the system preparation make up most of the rest.
Boiler type changes the bill more than brand
The biggest single choice is what kind of boiler you fit and whether you change the system. A like-for-like combi swap is the simplest job. Converting a regular or system boiler to a combi means removing tanks and cylinders and reworking pipes, so it costs more even though the new unit may be similar.
| Material | Typical | Usual range | Lifespan |
|---|---|---|---|
| Combi boiler (like-for-like) | £2,800 | £2,200 – £3,650 | 12-15 years |
| Regular (heat-only) boiler, tanks kept | £2,800 | £2,200 – £3,650 | 12-15 years |
| System boiler (existing cylinder kept) | £3,050 | £2,400 – £4,000 | 12-15 years |
| Convert regular or system to combi | £3,800 | £2,950 – £4,950 | 12-15 years |
If you are weighing a specific route, these are the typical mid-range costs with each type chosen:
- Combi, like-for-like: £2,800
- System boiler, existing cylinder kept: £3,050
- Regular boiler, tanks kept: £2,800
- Convert to combi: £3,800
Where quotes quietly climb
Flue position. Same position, standard flue is the cheapest case. Ask the installer to state in writing whether the flue is being moved. Vertical flues and relocations are the most common reason one quote is much higher than another.
Flush. A chemical clean is the standard line. A full power flush costs more and is worth asking about if your radiators have cold spots or the old system was sludgy. Check which one is in the price.
Controls. Under Boiler Plus rules in England, a new gas boiler must have a timer and room thermostat, and a gas combi installation must add one extra measure: flue gas heat recovery, weather compensation, load compensation, or smart controls with automation and optimisation. The boiler must also be at least 92% ErP efficient. So controls are not optional extras, and a quote that leaves them out is incomplete.
Cylinder work. If you are also replacing a hot water cylinder, see our guide to Hot water cylinder. An unvented cylinder is notifiable building work, so check that the installer is registered with a competent person scheme or will notify building control.
What to check on any quote
- The installer must be Gas Safe registered. Gas work by anyone else is illegal.
- The quote should name the boiler model, its efficiency and the warranty length.
- It should say which flue, which controls and which flush are included.
- It should list what is being removed and disposed of.
- Ask how the installer will meet the Boiler Plus requirement.
There is currently no requirement to fit a hydrogen-ready boiler. The government plans a 2026 decision on hydrogen for heating, and only if hydrogen gets a substantive role would that change, and then only from 2030. We would not pay extra for "hydrogen-ready" branding today.
Is a boiler the right spend?
If your boiler is old, replacing it is usually a like-for-like job with a predictable price. If you are thinking longer term, compare it against an air source heat pump. Our Air source heat pump guide shows the live figures. In England and Wales the Boiler Upgrade Scheme takes £7,500 off an air source or ground source heat pump, provided the installer is MCS certified. In Scotland, Home Energy Scotland offers a grant of up to £7,500 plus an optional £7,500 interest-free loan. Installing energy-saving materials, including heat pumps, is also 0% VAT until 31 March 2027.
Better insulation can also shrink the boiler you need. Our External wall insulation guide covers that side of the cost.
Check before you sign
Use the full New boiler guide for your size and region, then put your quote through our "is my quote fair" tool. Compare the total, not the unit price, and make sure each quote includes the same flue, controls and flush. A quote that looks cheap often has one of those left out.