New Boiler Costs UK 2025: Complete Pricing Guide
Your boiler's on its last legs. The engineer shakes their head and gives you the look. Time for a new one.
Now you're wondering what it'll cost. The honest answer: it depends. But "it depends" doesn't help you budget. So let's dig into the real numbers based on what homeowners across Britain are actually paying in 2025.
Average Boiler Costs in 2025
| Boiler Type | Boiler Only | Installed (Like-for-Like) | Installed (System Change) |
|---|---|---|---|
| Combi boiler | £800-£1,800 | £1,800-£3,000 | £2,500-£4,000 |
| System boiler | £900-£2,000 | £2,000-£3,500 | £2,500-£4,500 |
| Regular/conventional | £700-£1,500 | £1,500-£2,500 | £2,000-£3,500 |
Like-for-like replacement means swapping an old combi for a new combi in the same location. System change means moving the boiler, changing from regular to combi, or other significant modifications.
Real Homeowner Experiences
Sarah, Manchester (3-bed semi-detached): "Our 18-year-old Potterton finally gave up in January. We got three quotes ranging from £2,200 to £3,100 for a Worcester Bosch combi. The middle quote at £2,650 included a magnetic filter and system flush—that's what we went with. Installation took one day, and we've noticed our gas bills are about £15 less per month than with the old boiler."
James, Bristol (Victorian terrace): "Converting from our old back boiler to a combi was a bigger job than expected. The flue run was complicated, and they had to do some electrical work. Final bill was £3,400, but that included moving the boiler from the living room to the kitchen. Worth every penny—we've got the old fireplace back and proper hot water for the first time in years."
Margaret, Edinburgh (4-bed detached): "We needed a system boiler because of our two en-suites. The quotes ranged from £3,200 to £4,800. We chose a Vaillant at £3,900 with a 250-litre cylinder. The installer was brilliant—explained everything and left the house spotless. Six months on, no regrets."
What Type of Boiler Do You Need?
Combi Boilers
The most popular choice in UK homes, accounting for roughly 70% of all new installations. They heat water on demand—no storage cylinder needed.
Best for: 1-3 bedroom homes with 1-2 bathrooms. Homes without space for a hot water cylinder. Flats and smaller terraced houses.
Advantages:
- Compact, fits in a kitchen cupboard
- No cylinder to heat and store
- Hot water available instantly (no waiting for cylinder to heat)
- Generally cheapest option
- Ideal for smaller Victorian and Edwardian terraces where space is tight
Disadvantages:
- Struggles to supply multiple bathrooms simultaneously
- Flow rate limited by boiler capacity
- Not compatible with future heat pump without adding a cylinder
- Water pressure drops if someone runs a tap while you're showering
System Boilers
Work with a hot water cylinder. The boiler heats the cylinder, which stores hot water for use. Popular in larger British homes, particularly Edwardian and 1930s properties that were built with airing cupboards.
Best for: 3+ bedroom homes with 2+ bathrooms. Homes with high hot water demand. Families where multiple people shower in the morning.
Advantages:
- Better water pressure to multiple outlets
- Can supply several showers at once
- More compatible with solar thermal panels
- Easier transition to heat pump in future
- Hot water stored and ready—no waiting
Disadvantages:
- Needs space for cylinder (typically 1-2 square metres in cupboard)
- Hot water can run out if cylinder empties
- Slightly higher running costs (keeping cylinder warm)
- More components to maintain
Regular/Conventional Boilers
The traditional setup with separate boiler, hot water cylinder, and cold water tank (usually in the loft). Still common in older British homes, particularly pre-war properties.
Best for: Replacing existing regular systems. Older properties with complex pipework. Areas with low mains water pressure. Listed buildings where alterations are restricted.
Advantages:
- Works well with existing pipework
- Good for low water pressure areas (common in parts of Wales and rural England)
- Compatible with multiple heating zones
- Suits older radiator systems
Disadvantages:
- Needs most space (boiler, cylinder, tanks)
- Cold water tank in loft can freeze in harsh winters
- More components to maintain and potentially go wrong
Factors That Affect Price
Boiler Size
Boilers are sized by output in kW. For combi boilers, sizing depends on your hot water demand:
- 24-28 kW: Small homes, 1 bathroom, lower demand. £800-£1,200
- 30-35 kW: Average homes, 2-3 bedrooms, 1-2 bathrooms. £1,000-£1,500
- 35-42 kW: Larger homes, 4+ bedrooms, 2+ bathrooms. £1,300-£1,800
Don't oversize. A boiler that's too big for your home costs more to buy and runs less efficiently. An oversized boiler cycles on and off frequently, wasting energy and wearing out components faster.
Brand Premium
Brand affects both initial cost and reliability. From our analysis of Which? reliability data and engineer feedback:
| Brand | Price Tier | Warranty | Notes |
|---|---|---|---|
| Baxi | Budget | 7-10 years | Good value, reliable, British-designed |
| Ideal | Budget-Mid | 7-12 years | Popular with installers, Hull-based manufacturer |
| Worcester Bosch | Premium | 10-12 years | Market leader, highest rated by Which? |
| Vaillant | Premium | 10-12 years | German engineering, excellent efficiency |
| Viessmann | Premium | 10-12 years | High-end German brand, quieter operation |
Premium brands cost 20-40% more but typically offer longer warranties and better long-term reliability. For a boiler you'll live with for 10-15 years, the premium often makes sense. Worcester Bosch consistently tops reliability surveys, but Baxi and Ideal offer excellent value for tighter budgets.
Installation Complexity
Simple replacement (same location, same type): 4-6 hours labour. £600-£1,000 in labour costs. This is the most straightforward job.
Relocation: Moving a boiler to a new location adds pipework, potentially flue work, and more time. Add £500-£1,500. Common when converting a kitchen or freeing up a bedroom cupboard.
System change: Converting from regular to combi, or adding a cylinder, involves significant replumbing. Add £800-£2,000. Typical when modernising Victorian or Edwardian homes.
Flue complications: Long flue runs, multiple bends, or vertical flues all add cost. £200-£500. Particularly relevant in terraced houses or flats.
Regional Price Variations
Installation costs vary across Britain:
- London and South East: Highest prices, typically 15-25% above national average
- Midlands and North West: Around national average
- Scotland and Wales: Often 5-10% below national average
- Rural areas: May be higher due to travel time and fewer competing installers
Additional Work
Your quote might include:
- System flush (recommended): £300-£500
- Magnetic filter (extends boiler life): £100-£200
- Radiator upgrades: £150-£300 per radiator
- Smart thermostat (Hive, Nest, tado°): £150-£350
- Gas safety certificate: Usually included
- Chemical inhibitor treatment: £50-£100
How to Get the Best Price
1. Get Multiple Quotes
At least three, ideally five. Prices vary 20-40% for the same work. Don't accept the first quote, no matter how reasonable it seems.
2. Compare Like for Like
Make sure quotes specify:
- Exact boiler model (not just "equivalent")
- What's included (flush, filter, thermostat)
- Warranty length and conditions
- What happens if problems arise during installation
- Whether scaffolding is needed for flue work
3. Check Gas Safe Registration
Any engineer installing a gas boiler must be Gas Safe registered. Check on the Gas Safe Register website using their ID number. This is non-negotiable—illegal installations void insurance and risk lives.
4. Ask About Warranties
Manufacturer warranties typically require annual servicing to remain valid. Ask what servicing costs and whether it's included in the quote. A 10-year warranty is worthless if you can't afford the £80-£120 annual service.
5. Consider Timing
Summer is slower for heating engineers. You might negotiate better prices in July than in February when everyone's boiler has broken down. Spring and autumn are also busy—installers are preparing for winter or dealing with autumn breakdowns.
Victorian and Period Property Considerations
Older British homes present specific challenges:
- Solid walls: May need longer flue runs or different flue terminals
- Cast iron radiators: Work well with combi boilers but may need balancing
- Complex pipework: Decades of additions and modifications can complicate replacement
- Listed building restrictions: May limit where boilers and flues can go
- Poor insulation: May need larger output boiler to compensate for heat loss
Should You Get a Boiler or a Heat Pump?
With the Boiler Upgrade Scheme offering £7,500 towards heat pumps, it's worth comparing:
| Factor | Boiler | Heat Pump |
|---|---|---|
| Upfront cost (after grant) | £2,000-£3,500 | £2,500-£8,000 |
| Running costs (annual) | £500-£800 | £400-£700 |
| Lifespan | 12-15 years | 15-20 years |
| Future-proofing | Gas phase-out coming | No concerns |
| Works in all homes | Yes | Needs good insulation |
| Space required | Minimal | Outdoor unit + cylinder |
If your home is well-insulated (EPC rating C or better) and you can accommodate a hot water cylinder, a heat pump might cost similar to a boiler after the grant—with lower running costs and a future-proof heating system.
If your home has poor insulation, no space for a cylinder, or you need a quick replacement, a new boiler is still a sensible choice. Modern condensing boilers are efficient and will last another decade or more.
Frequently Asked Questions
Q: How long does boiler installation take?
A: A like-for-like replacement typically takes 4-8 hours (one day). Moving location or changing system type may take 2-3 days.
Q: Can I install a boiler myself?
A: No. Gas boiler installation must be done by a Gas Safe registered engineer. This is a legal requirement, not optional.
Q: How often should I service my boiler?
A: Annually. This maintains warranty validity, ensures safety, and catches problems early. Budget £80-£120 per year.
Q: What's a system flush and do I need one?
A: A power flush cleans sludge from your heating system. It's strongly recommended when fitting a new boiler to an old system—prevents contamination damaging your new boiler.
Q: Should I get a magnetic filter?
A: Yes. A magnetic filter (like MagnaClean) catches debris and extends boiler life. At £100-£200, it's cheap insurance.
The Bottom Line
A new boiler costs £1,800-£3,500 for most British homes, including installation. Budget brands start lower. Premium brands with extended warranties push higher. Complex installations add more.
Get multiple quotes, compare specifications carefully, and use only Gas Safe registered engineers. A good installation with quality equipment will serve you well for 12-15 years.
And at least consider getting a heat pump quote alongside your boiler quotes. The economics have shifted enough that it's worth comparing, even if you ultimately choose a boiler. With the £7,500 BUS grant available until 2028, heat pumps are more affordable than ever for homes that suit them.