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01 · Ask
Repair, replace or upgrade?
Cold rads, no hot water, F22 fault code? Describe what's happening — the AI tells you if it's a £150 repair or a £3k replacement.
Finance your new boiler.
Pay-monthly, 0%, buy-now-pay-later — how installers structure boiler finance and what it actually costs.
✓ Updated May 2026✓ Free quotes✓ Vetted pros
20,000+UK homeowners
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Hire a boiler engineer. Without the warranty void.
Read the brief on sizing, brands and warranty rules — then let Three local engineers quote on the right boiler for your house.
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02 · Read the brief
Walk in informed
kW sizing, modulation ratios, Benchmark cert, manufacturer warranty terms. Know what to ask before they recommend the most expensive box on the van.
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03 · Compare
Compare 3 engineer quotes
Three local engineers come back with itemised quotes — boiler, flue, controls, power-flush, commissioning — so the like-for-like vs upgrade choice is yours.
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Top tips
Hiring a boiler engineer, without the regret.
Four moves that separate a smooth job from a nightmare.
Get a Gas Safe ID before letting them in.
Boilers are gas appliances. Anyone working on yours must be Gas Safe registered — and on the right scheme for your fuel (LPG, oil, natural gas are separate).
Demand the Benchmark certificate.
Every new boiler comes with a Benchmark commissioning checklist. Without it, the manufacturer warranty is void — and the certificate goes in your seller's pack later.
Size the boiler to the radiators, not the house.
Oversized combis short-cycle, wear out fast and cost more to run. A heat-loss calc — not a 'same as before' swap — is the sign of a careful installer.
Power-flush before fitting.
On a 10-year-old system, sludge will write off your new boiler's heat exchanger in 18 months. A power-flush should be quoted; if it's not, ask why.
Costs & timeline
Know what it costs. Know when it ends.
Indicative UK ranges and what affects price.
Cost range
By job type
Inc. VAT · 2026
Source: NMT quotes
Source: NMT quotes
Boiler service (annual)
£80–£150
Combi boiler swap (like-for-like)
£1.8k–£3k
Combi boiler upgrade (premium)Vaillant/Viessmann tier
£2.8k–£4.5k
System boiler + cylinder
£3k–£5.5k
Power flush
£450–£900
Conversion from back-boilerInc. removal + replumb
£3.5k–£6k
!
Quote spread is typically ± 18% — always get 3 quotes.
At a glance
Infographic · VideoThe Boiler Engineer briefing.
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Boiler Engineer explained
Boiler installations can cost £2,000-£5,000 upfront. Many UK installers offer finance through partners — typically 0% over 1-2 years or longer-term loans at 6-15% APR. This guide covers UK 2026 boiler finance options and whether to use them.
Common Finance Options
- 0% APR over 24 months — interest-free; spread cost.
- 9.9% APR over 5 years — common longer-term option.
- HomeCare bundle — install + ongoing service in one monthly fee.
- Buy now pay later (BNPL) — defer up to 12 months interest-free.
- Personal loan — own bank, often cheaper than installer finance.
Typical Costs
| Boiler cost | 0% over 24 months | 9.9% over 5 years |
|---|---|---|
| £2,500 | £104/mo (£2,500 total) | £53/mo (£3,158 total) |
| £3,500 | £146/mo (£3,500 total) | £74/mo (£4,421 total) |
| £5,000 | £208/mo (£5,000 total) | £106/mo (£6,316 total) |
Pros and Cons
- Pro: spread cost, avoid lump sum.
- Pro: 0% means no extra cost (if you'd pay anyway).
- Con: longer-term finance adds significant interest.
- Con: locked into provider for service if HomeCare bundle.
- Con: harder to compare costs with monthly basis.
UK Regulations
- Finance providers regulated by FCA.
- Credit check usually required.
- Cooling-off period typically 14 days.
Common Problems
- Hidden interest — "0%" may have hidden setup fees.
- Long commitment — 5-year finance ties you to provider.
- Credit declined — may need bigger upfront deposit.
- HomeCare lock-in — can't easily switch service provider during finance.
Frequently Asked Questions
Is 0% finance really 0%?
Genuine 0% if disclosed clearly. Sometimes prices are inflated to hide interest — compare total cost.
Should I use personal loan instead?
Often cheaper. Compare APR: personal loans typically 4-8% vs installer 9-15%.
What's a boiler subscription?
HomeCare-style — monthly fee includes install over years plus ongoing service. Like Netflix for boilers.
Can I pay off early?
Most finance allows it. Check for early repayment fees.
What credit score is needed?
Usually fair to good (600+). Bad credit may need guarantor or larger deposit.
Are there grants for new boilers?
Limited — ECO scheme for low-income households. Boiler Upgrade Scheme for heat pumps. Check eligibility.
This guide was written with AI assistance and is intended for general information only. Prices are estimates based on UK averages and may vary by region. Always get at least three quotes and consult a qualified professional before starting any work.
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