Typical new boiler prices in the UK
The figures below are for a new gas boiler supplied and fitted by a Gas Safe registered engineer, including removal of the old boiler, a system clean and standard controls. They are typical ranges, not quotes. Your price depends on the boiler you choose, your home and where you live.
| Job | Typical cost, supply and fit | Usually suits |
|---|---|---|
| Combi boiler, like-for-like swap | Typically £1,800 to £3,500 | Flats and houses with one or two bathrooms |
| System boiler, keeping the existing cylinder | Typically £2,200 to £4,000 | Homes with two or more bathrooms and good mains pressure |
| Regular (heat-only) boiler, keeping the tanks and cylinder | Typically £2,000 to £4,000 | Older homes with low mains pressure or a loft tank setup |
| Converting a system or regular setup to a combi | Typically £3,000 to £5,000 | Smaller homes freeing up cupboard and loft space |
| New unvented cylinder alongside a system boiler | Typically adds £1,000 to £2,500 | Larger homes with several showers in use at once |
For a closer look at the combi job itself, including conversions and extra pipework, see our guide to combi boiler installation cost.
What changes the price
The boiler itself
Boilers from Worcester Bosch, Vaillant and Viessmann tend to sit at the upper end of the range, while entry models from Ideal, Baxi and other makers cost less. Output matters too. A 25kW combi costs less than a 35kW model, but you should pay for the output your home needs, not the biggest one on offer. An engineer sizes a combi mainly on hot water demand and a system or regular boiler on the heat loss of the house.
The type of installation
Swapping a combi for a combi in the same spot is the cheapest job, often done in a day. Moving the boiler to another room, changing boiler type or removing tanks from the loft adds labour, pipework and sometimes a second day, which is why conversions cost more.
Labour and location
Day rates for Gas Safe registered engineers are higher in London and the South East than in most other regions. Large national firms often quote higher than local independent installers, though they may include longer warranties or finance options.
Access, flue and pipework
A boiler in a tight cupboard or loft takes longer to fit. A new flue route, a vertical flue through the roof or an extended flue kit all add cost. Many older homes also need a larger gas pipe from the meter, because modern combis can draw more gas than the old pipe was sized for.
Warranty length
Several manufacturers offer extended warranties, often 7 to 12 years, when the boiler is fitted by one of their accredited installers and serviced every year. Longer warranty packages usually come with a higher installation price, so compare what you get as well as what you pay.
Moving the boiler
Moving a boiler to a new room, for example from a kitchen into a loft or utility room, means new gas, water and heating pipes, a new flue route and a new condensate run. That typically adds £500 to £1,500 to the job, depending on the distance and how much floor or wall has to be opened up.
Combi, system or regular: which do you need?
The cheapest boiler is usually the same type you already have, because the pipework is in place. Change type only when there is a good reason.
- Combi: heats water on demand from the mains, with no tanks or cylinder. Good for one bathroom and decent mains flow, but struggles when two showers run at once.
- System: heats a hot water cylinder, usually unvented, with most parts built in. Better for busy households with several bathrooms.
- Regular or heat-only: works with a cold water tank in the loft and a vented cylinder. Often kept in older homes with low mains pressure or older radiators that may not cope with higher pressure.
An engineer should measure your mains water flow and pressure before recommending a combi. If the flow is weak, a combi can leave you with disappointing showers.
What a good quote should include
Quotes vary a lot in what they cover, so ask for an itemised price. A complete quote for a new boiler normally includes:
- removal and disposal of the old boiler and any tanks being taken out
- the new boiler, flue kit and condensate pipe, with the condensate pipe run and insulated to reduce the risk of a frozen condensate pipe
- a chemical clean or flush of the system and a corrosion inhibitor, as the manufacturer and British Standards expect
- a magnetic system filter, which many manufacturers need for the full warranty
- time and temperature controls, and in England an extra energy-saving measure on combi installs, such as a smart thermostat with automation and optimisation, or weather compensation
- registration of the work with Building Control through Gas Safe, and the completed Benchmark checklist
- registration of the manufacturer warranty
If the system water is very dirty, the installer may recommend a full powerflush instead of a basic clean, which costs extra.
Grants and help with the cost
Help towards a new boiler changes often and depends on where you live, your income and whether anyone in the household receives certain benefits. Some government and energy supplier schemes have funded heating upgrades for eligible households in the past, but availability and rules change. The Boiler Upgrade Scheme in England and Wales gives grants towards heat pumps and biomass boilers, not like-for-like gas boilers.
To see what is available now, check GOV.UK, ask your energy supplier and contact your local council. In Scotland, Home Energy Scotland is a good starting point. Be wary of cold callers offering a free boiler, and never let anyone who is not Gas Safe registered carry out the work.
How to keep the cost down
- Get at least three written quotes from Gas Safe registered installers and compare them line by line.
- Stick with the same boiler type and position unless there is a clear benefit to changing.
- Ask whether the recommended output is based on your hot water use or heat loss, rather than simply fitting a larger model.
- Book outside the winter rush if your old boiler is still working, as installers are often less busy in late spring and summer.
- Check what the warranty needs from you, usually an annual service. Our boiler service cost guide shows what that typically adds each year.
If your current boiler has only just broken down, get a repair price as well before committing. Many faults, such as a worn relief valve or a leaking pump seal, are much cheaper to fix than a new boiler, and our guide to a boiler leaking water shows typical prices for those. Our guide on whether to repair or replace a boiler walks through how to decide.