Cost of a New Boiler in the UK (2025)
A new boiler costs £2,000–£4,500 fully installed. The price depends on boiler type, brand, property size, and whether pipework changes are needed.
What type of boiler do I need?
A combi boiler heats water on demand and is the most popular choice for homes with 1–2 bathrooms — no need for a hot water cylinder. A system boiler uses a hot water cylinder and suits homes with higher demand. A heat-only (regular) boiler is found in older systems and requires both a cylinder and a cold water tank. For most modern homes, a combi boiler replacement is the straightforward choice.
How long does installation take?
A like-for-like combi boiler swap (same location, same type) typically takes one full day. Moving the boiler to a different location adds a day. Switching from a system or heat-only boiler to a combi usually takes 2–3 days due to the pipework changes and removal of the cylinder and tanks.
Boiler brands: what to choose
Worcester Bosch and Viessmann consistently top consumer and engineer surveys for reliability. Vaillant and Ideal are also well-regarded. Cheaper brands (Alpha, Baxi budget ranges) have higher fault rates. A slightly more expensive, reliable boiler will save money in servicing and repairs over its lifetime.
Cost Breakdown
All prices are indicative UK averages for 2025. Actual costs vary by location, specification, and contractor. London and South East rates are typically 20–35% higher.
| Item | Low | High |
|---|---|---|
| Budget combi (supply & fit) | £1,800 | £2,500 |
| Mid-range combi (supply & fit) | £2,200 | £3,200 |
| Premium combi (supply & fit) | £2,800 | £4,000 |
| System boiler (supply & fit) | £2,500 | £4,500 |
| Conversion to combi | £3,000 | £5,000 |
| Power flush (when replacing) | £300 | £600 |
What Affects the Cost?
- ✓Boiler brand and output (kW rating)
- ✓Whether it is a like-for-like swap or a system change
- ✓Flue relocation requirements
- ✓Age and condition of existing pipework
- ✓Location — London typically 20–30% more expensive
- ✓Warranty length — longer warranties increase upfront cost but save long-term
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Post a Job — It's FreeFrequently Asked Questions
How long should a new boiler last?
A quality boiler, serviced annually, should last 10–15 years. Budget models may start experiencing issues after 8–10 years. Worcester Bosch and Viessmann regularly last 15+ years with proper maintenance.
Is there any government help towards a new boiler?
The Boiler Upgrade Scheme offers grants for heat pumps, not gas boilers. Some energy suppliers offer boiler replacement schemes for households on benefits. Check gov.uk and your energy supplier for current schemes.
Should I service my new boiler every year?
Yes — annual servicing is required to maintain the manufacturer warranty and keeps efficiency high. An unserviced boiler can increase energy bills by 10–15% and fail earlier.
Can I get a boiler on finance?
Yes — many Gas Safe engineers and boiler companies offer 0% or low-interest finance over 3–10 years. Monthly payments typically range from £30–£80 depending on the boiler cost and term.