Once a year, for both gas and oil boilers. Manufacturers recommend it, and most new boiler warranties depend on it. Gas boilers must be serviced by a Gas Safe registered engineer; oil boilers should be serviced by a competent technician, ideally OFTEC registered.
Leaving it longer rarely saves money. Minor wear goes unchecked, efficiency drops and the chance of a winter breakdown rises. Booking your boiler service in late summer or autumn means any problems are found before you need the heating every day.
Why once a year?
A boiler goes through thousands of heating cycles a year. In that time, deposits build up on the burner and heat exchanger, seals age, condensate traps partly block, and the expansion vessel can lose pressure. On oil boilers, the nozzle wears and filters collect sludge.
None of these usually cause an immediate failure, but together they reduce efficiency and increase the risk of breakdowns and unsafe combustion. A yearly service catches them early.
Servicing and your warranty
Most boiler manufacturers make their warranty conditional on a service every 12 months, recorded in the boiler’s Benchmark logbook or the manufacturer’s online system. Miss one and a later claim may be refused.
The first service is usually due about 12 months after installation. Keep every service record in a safe place.
What’s checked during a service
| Check | Gas boiler | Oil boiler |
| Visual inspection of boiler, flue and pipework | Yes | Yes |
| Burner and heat exchanger cleaned as needed | Yes | Yes |
| Nozzle and oil filters replaced | No | Yes |
| Combustion analysis | Yes | Yes |
| Condensate trap checked and cleaned | Yes | Yes (condensing models) |
| Safety devices tested | Yes | Yes |
| System pressure and expansion vessel checked | Yes | Yes |
| Oil supply line and fire valve checked | No | Yes |
When to book sooner
Don’t wait for the anniversary if:
- The boiler locks out or shows fault codes
- Pressure keeps dropping
- You hear banging, gurgling or whistling
- There’s a smell of gas, oil or fumes
- You see soot or staining around the boiler or flue
- The heating or hot water isn’t as hot as normal
If you smell gas, turn off the supply at the meter if it’s safe, open windows, avoid switches and call the National Gas Emergency Service on 0800 111 999. Our guide on what to do if your boiler breaks down covers the first steps.
Servicing in rural Herefordshire
Across Herefordshire, many homes in villages around Hereford, Leominster, Bromyard and Ledbury are off the mains gas network and rely on oil. Oil boilers are more sensitive to wear than gas boilers, so an annual service is especially important. For gas homes in Hereford and the market towns, the same once-a-year rule applies.
If your boiler is getting old and needing more work at each service, it may be worth weighing up a new boiler.
Frequently asked questions
Is it OK to service my boiler every two years?
It’s not recommended. Most warranties require annual servicing, and problems are more likely to develop between visits. A yearly service is usually cheaper than an avoidable breakdown.
What’s the best time of year for a service?
Late summer and early autumn work well, as any repairs can be done before winter. Any time of year is fine if it’s roughly 12 months since the last one.
Can a landlord’s gas safety check replace a service?
No. A gas safety check confirms appliances are safe; a service keeps the boiler working properly and supports the warranty. Landlords often book both together.
Do new boilers need a service in the first year?
Yes. The first service is normally due around 12 months after installation to keep the manufacturer’s warranty valid.
Boiler due its service?
Give us a call on 07742 183 564 or drop us a message and we’ll get you booked in.