Guide: Boilers
Boiler service cost in the UK and what it includes
An annual boiler service is the check that keeps every major manufacturer warranty valid. It is a visual and combustion inspection by a Gas Safe registered engineer, not a deep clean. Prices vary by location and whether you are an existing customer, so get a quote and confirm what is included before booking.
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Get matchedWhat a compliant service includes
- A visual inspection with the case off: combustion chamber, heat exchanger, burner and fan.
- Flue gas analysis (FGA) under high and low fire.
- A gas pressure test, working and standing.
- A condensate trap clean and refill.
- An operating-pressure check, cold and hot.
- A visible pipe and joint inspection.
- A service record entered in the boiler manual.
What is not included
- A magnetic filter clean, often a small add-on and worth it if not done in two years.
- A powerflush, which is a separate job.
- Diverter valve or pump replacement, charged as parts and labour separately.
- Smart controls install or pairing.
Why "free with insurance" usually is not free
Boiler-cover plans bundle the annual service so it looks free, but you pay a monthly premium that, over a year, is materially more than a standalone service plus the occasional repair.
The cover plan only really pays back if your boiler is old, you have no emergency fund, and you actively use the call-out side. For most households a standalone service plus a contingency for repairs costs less.
Service vs strip-down inspection
A standard service is a check, not a clean. A strip-down inspection removes the burner, brushes the heat exchanger and replaces combustion seals. Most engineers suggest a strip-down every few years in a hard-water area, or sooner if FGA readings are drifting. Annual services for several years, then a strip-down, is the sensible pattern.
Warranty implications
Every major UK boiler manufacturer requires evidence of an annual service to honour the warranty. A signed service record in the boiler manual is normally enough. Missing a year typically voids the rest of a multi-year manufacturer warranty, which is the single most expensive mistake people make.
What it costs
- Standalone annual service
- Get a quote Varies by engineer location and whether you are an existing customer.
- Service plus a landlord gas record
- Get a bundled quote Bundling the service with the CP12 / LGSR in one visit is usually cheaper than two visits.
We do not publish a single fixed price; it depends on your engineer and whether extras such as a filter clean are added. Get a quote and confirm what is and is not included.
How to choose a vetted trade
- Use a Gas Safe registered engineer and ask for their registration number; the work is illegal otherwise.
- Confirm the service record will be signed in the boiler manual, which is what keeps your warranty valid.
- Ask up front whether a magnetic filter clean is included or charged as an extra.
Frequently asked questions
How often does a boiler need servicing?
Once a year. An annual service by a Gas Safe registered engineer is what keeps a manufacturer warranty valid, and most warranties are voided by a missed year. It also catches combustion and pressure problems early, before they become a no-heat emergency.
Is a boiler-cover plan cheaper than paying per service?
Usually not, for most households. The monthly premium over a year tends to cost more than a standalone service plus an occasional repair. Cover plans pay back mainly when the boiler is old, you have no emergency fund, and you use the call-out side often.
Does a service include a powerflush or filter clean?
No. A standard service is an inspection, not a clean. A powerflush is a separate job, and a magnetic filter clean is usually a small add-on. Ask what is included before booking so the quote is not topped up with extras on the day.
Sources
Editor, Sorted Property
Oliver leads Sorted Property's editorial coverage of UK home services. He researches and writes the plain-English guides that help homeowners choose between installers and trades, drawing on the standards set by bodies such as MCS, TrustMark, the Energy Saving Trust and the Property Care Association, and is clear about what to check before any work starts.
Last reviewed: 11 June 2026