What’s included in a boiler service? The full checklist (and what it isn’t)
An annual boiler service is one of those jobs where the customer can’t easily see what they paid for — which is exactly why it helps both homeowners and engineers to know what a proper service includes. Here’s the checklist, how long it takes, and the difference between a service and the landlord gas safety check people often confuse it with.
The service checklist
During an annual service, a Gas Safe registered engineer will typically:
- Visually inspect the boiler, controls and visible pipework for corrosion, leaks and correct installation
- Check the flue is safe, unobstructed and terminated correctly, and analyse the flue gases with a combustion analyser
- Check the gas pressure and heat input are to the manufacturer’s specification
- Inspect seals, the condensate trap and pipe, and safety devices
- Clean components such as the heat exchanger, burner and injectors where the manufacturer’s instructions require it
- Fire the boiler and check it operates correctly, then record the results and any defects
How long it takes and what it costs
A straightforward service on an accessible, well-maintained boiler takes around 30–60 minutes. Prices vary by region, but most UK homeowners pay somewhere in the £70–£120 range for a one-off service; service plans spread the cost monthly.
If the analyser readings or inspection show a fault, fixing it is normally quoted as a separate repair rather than absorbed into the service price — a good engineer explains the defect, the risk and the price before doing more work.
A service is not a gas safety check
The two get conflated constantly. A boiler service is maintenance, done to the manufacturer’s instructions, keeping the appliance efficient and the warranty valid. A landlord gas safety check is the legal annual safety inspection of every gas appliance and flue in a rented property, recorded on a CP12 — it checks the appliances are safe, not that they’re maintained.
Landlords generally need both each year; many engineers sensibly do them in a single visit. Homeowners have no legal obligation to service the boiler — but see the warranty point below.
Why annual servicing matters
- Warranty: almost every boiler warranty and guarantee requires proof of an annual service by a Gas Safe engineer — miss one and a £1,500 heat exchanger failure can become your bill
- Safety: the combustion check catches problems that can lead to carbon monoxide production before they become dangerous
- Efficiency: a maintained boiler burns less gas for the same heat
- Timing: book in summer — engineers have availability, and you find faults before the heating season, not during it
For engineers: turning services into a round
Servicing is the most predictable revenue in heating — every customer needs one every year — yet most engineers rely on the customer remembering. TradeHub OS logs the service date against every customer and sends automatic reminders when the next one is due, so the booking comes back to you. The job, service record, invoice and payment all live in one thread.
This guide is general information for UK trades and landlords, not legal advice. Always refer to the current regulations and official guidance from the HSE, Gas Safe Register or your competent-person scheme.
