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.
Annual service, breakdown repair or full combi swap — quoted with the make, kW and warranty up front.
Read the brief on sizing, brands and warranty rules — then let Three local engineers quote on the right boiler for your house.
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.
kW sizing, modulation ratios, Benchmark cert, manufacturer warranty terms. Know what to ask before they recommend the most expensive box on the van.
Three local engineers come back with itemised quotes — boiler, flue, controls, power-flush, commissioning — so the like-for-like vs upgrade choice is yours.
Ready when you are
Enter your postcode and get free quotes from local pros.
Four moves that separate a smooth job from a nightmare.
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).
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.
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.
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.
Indicative UK ranges and what affects price.
By job type
Quote spread is typically ± 18% — always get 3 quotes.
Visual breakdown of costs, timelines and the questions you should be asking.
Boiler Engineer quick-view

Boiler Engineer explained
Everything you need to know before hiring a boiler engineer.
A boiler engineer is a specialist technician responsible for the installation, maintenance, and repair of central heating systems. In the UK, where reliable heating is a necessity for most of the year, these professionals ensure your home remains warm and your hot water remains consistent.
Beyond simple repairs, boiler engineers handle complex system upgrades, emergency breakdowns, and essential annual safety checks. Whether you are upgrading to a modern energy-efficient combi boiler or need a Landlord Gas Safety Record, a qualified engineer is the only person legally permitted to work on your gas appliances.
Most engineers specialise in natural gas, but many are also qualified to work on LPG, oil-fired systems, or emerging low-carbon technologies like heat pumps. Their work is critical not just for comfort, but for the safety of your household, preventing dangerous issues like carbon monoxide leaks.
Hiring a boiler engineer usually follows a structured process to ensure safety and compliance with UK building regulations. Here is what you can typically expect:
In the UK, it is a legal requirement under the Gas Safety (Installation and Use) Regulations 1998 that anyone working on gas appliances must be on the Gas Safe Register. Attempting DIY gas work is not only illegal but can be fatal due to the risks of explosions or silent carbon monoxide poisoning.
Professional engineers bring more than just legal compliance; they provide technical expertise that ensures your system runs at peak efficiency. This can save you hundreds of pounds on annual energy bills. Furthermore, most manufacturer warranties (which can last up to 10-12 years) are only valid if the boiler is installed and serviced annually by a Gas Safe registered professional.
Hiring a pro also ensures that your home insurance remains valid. Many insurers will refuse to pay out for fire or water damage caused by heating systems that were not maintained or installed by a qualified tradesperson.
Boiler pricing varies significantly based on the brand of the unit, the complexity of the pipework, and your location in the UK. Below are estimated costs for common services in 2025/26.
| Service | Low £ | High £ | Notes |
|---|---|---|---|
| Annual Boiler Service | £80 | £150 | Includes safety checks and efficiency cleaning. |
| Emergency Call-out (1hr) | £90 | £180 | Excludes parts; higher rates for nights/weekends. |
| Combi-to-Combi Replacement | £1,800 | £3,200 | Straight swap in the same location. |
| System-to-Combi Conversion | £2,500 | £4,500 | Includes removing tanks and upgrading pipework. |
| Gas Safety Certificate (CP12) | £60 | £120 | Standard requirement for UK landlords. |
| Magnetic System Filter Install | £150 | £250 | Protects the boiler from sludge buildup. |
Total costs are influenced by the boiler's "kW" output (power), the length of the flue required, and whether you need to relocate the unit to a different room. Engineers in London and the South East typically charge 20-30% more for labour than those in the North.
Finding a reliable engineer requires more than just picking the lowest price. Use this checklist to ensure you are hiring a competent professional:
3 Questions to ask before hiring:
You should have your boiler serviced once every 12 months. This is essential for maintaining the manufacturer's warranty, ensuring the unit is running safely, and catching small faults before they become expensive breakdowns.
A simple "like-for-like" swap usually takes one day. However, if you are converting from an old system with a water tank to a modern combi boiler, or moving the boiler to a new location, it can take 2 to 3 days.
Yes, you should turn off the water supply and the boiler immediately. A leak can damage the internal electronics (PCB), leading to a much more expensive repair, or cause significant damage to your home's flooring and ceilings.
Most modern condensing boilers are designed to last between 10 and 15 years. Regular annual servicing and the installation of a magnetic filter can help extend this lifespan toward the upper end of that range.
Describe the job in plain English. The AI asks a few smart questions, then tells you whether a boiler engineer is the right call, what it should cost, and what to ask before they start.
Replacing an old back boiler (behind a fireplace) with a modern combi or system boiler. UK 2026 costs and detail.
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READ GUIDE →GuideAnnual boiler service: what's checked, why it matters, and what UK boiler servicing costs in 2026.
READ GUIDE →GuideGas Safe Register: what it is, why every gas engineer must be on it, and how to verify before hiring.
READ GUIDE →GuideCP12 / landlord gas safety certificate: legal requirement, cost, and what's checked. UK 2026 guide.
READ GUIDE →GuidePower flushing: what it is, when it's needed, and what it costs in the UK in 2026.
READ GUIDE →