When your existing boiler starts showing signs of age or inefficiency, a replacement becomes inevitable. As trusted boiler installers in Eastleigh and throughout Hampshire, we’re often asked about the costs involved. This comprehensive guide will break down everything you need to know about boiler replacement costs in 2025.
Average Boiler Replacement Costs
The cost of replacing your boiler will vary depending on several factors, but as a general guide, you can expect to pay:
Combi to Combi Swap:
- Budget models: £1,800 – £2,300
- Mid-range models: £2,300 – £3,000
- Premium models: £3,000 – £4,500
System to System Boiler:
- Budget models: £2,000 – £2,500
- Mid-range models: £2,500 – £3,200
- Premium models: £3,200 – £4,800
System to Combi Conversion:
- Budget models: £2,800 – £3,500
- Mid-range models: £3,500 – £4,200
- Premium models: £4,200 – £5,500
These prices typically include the boiler, installation, system flush, filters, controls, and labour. However, every home is different, and your specific requirements might affect the final cost.
Factors That Influence Boiler Replacement Cost
1. Boiler Type and Brand
Different boiler types come with different price tags:
Combi Boilers: These provide hot water and heating on demand without the need for a separate water tank. They’re ideal for smaller properties with limited space and moderate hot water demands.
System Boilers: These work with a hot water cylinder but don’t require a cold water tank in the loft. They’re suitable for properties with higher hot water demands.
Regular (Conventional) Boilers: These work with both a hot water cylinder and a cold water tank. They’re typically found in older properties and are good for homes with multiple bathrooms or low water pressure.
As for brands, Worcester Bosch, Vaillant, and Ideal tend to be premium options, while Baxi and Glow-worm offer more budget-friendly alternatives.
2. Installation Complexity
The complexity of your installation significantly impacts cost:
Straightforward swap: If you’re replacing like-for-like in the same location, this keeps costs down.
System conversion: Converting from a conventional to a combi boiler involves more work and potentially removing water tanks.
Relocation: Moving your boiler to a different position requires additional pipework and potentially building works.
Accessibility issues: Difficult access can increase labour time and costs.
3. Additional Components
Several additional components might be required:
Magnetic filter: £100-£150, protects your system from sludge build-up.
Scale reducer: £100-£200, essential in hard water areas to prevent limescale.
System flush: £300-£500, removes debris and sludge from your existing pipework.
Smart controls: £150-£350, allows for more efficient control of your heating system.
4. Property Size and Heat Demand
Larger properties require more powerful boilers which typically cost more:
Small flats/1-2 bedroom properties: 24-27kW boilers usually suffice.
3-4 bedroom houses: 28-34kW boilers are typically recommended.
Larger properties: 35-42kW boilers may be necessary.
Ways to Save on Your Boiler Replacement
Finance Options
Many homeowners don’t realise that boiler replacement doesn’t have to be paid for upfront. At LW Gas, we offer various finance options including:
- Interest-free credit for 12 months
- Low-interest options spread over 2-10 years
- Pay-as-you-save plans
These options make a new, efficient boiler much more accessible.
Timing Your Replacement
If your boiler isn’t in an emergency situation, consider timing your replacement:
Summer installation: Engineers are typically less busy in summer, and some companies offer seasonal discounts.
End of month/quarter: Some installation companies may offer better deals to meet targets.
Energy Efficiency Savings
While a new boiler requires upfront investment, the energy savings can be substantial:
Old G-rated boiler to new A-rated boiler: Potential annual savings of £300-£500 on energy bills.
Smart controls: Adding smart controls can save an additional 10-15% on heating costs.
Over the 10-15 year lifespan of your new boiler, these savings can significantly offset the initial cost.
What to Expect During a Quotation
A reputable boiler installation company should provide:
- A home visit to assess your specific requirements
- A detailed breakdown of costs
- Multiple options at different price points
- Clear explanation of the installation process
- Information about warranties and aftercare
Beware of companies offering quotes without visiting your property, as these rarely account for the specific characteristics of your home and heating system.
The Hidden Cost of Delaying Replacement
Continuing to run an inefficient boiler can cost you more than you might realise:
- Higher monthly energy bills
- Increasing repair costs
- Risk of complete breakdown (often at the most inconvenient time)
- Decreased property value
In many cases, these ongoing costs outweigh the investment in a new, efficient system.
Get a Personalised Quote
Every home is unique, and the most accurate way to determine your boiler replacement cost is with a personalised quotation. As experienced boiler installers in Eastleigh and throughout Hampshire, LW Gas provides detailed, no-obligation quotes tailored to your specific requirements.
Contact us today to arrange your free home assessment and receive expert advice on the most cost-effective boiler replacement for your home.
