You should have your boiler serviced once a year — every 12 months — by a Gas Safe registered engineer. For homeowners, an annual service isn’t a legal requirement, but it’s strongly recommended, and most manufacturers require it to keep your warranty valid. For landlords it’s slightly different: the law (the Gas Safety (Installation and Use) Regulations 1998) requires an annual Gas Safety Check, known as a CP12, on gas appliances — that’s a safety inspection rather than a full service, though many landlords sensibly arrange both together. Servicing yearly keeps your boiler running efficiently, cuts the risk of a breakdown in the depths of winter, and catches small faults before they turn into big bills. We’re Gas Safe registered (657972) and service boilers in homes across West and North West London — you can book an annual boiler service any time.
It’s one of the most common questions we’re asked on the doorstep, usually somewhere around October when the heating goes back on. The short answer is simple — once a year — but the why, and what counts as a “service” versus a legal safety check, trips a lot of people up. Here’s the clear version.
How often should you service your boiler?
Service your boiler once every 12 months. That’s the advice from boiler manufacturers and Gas Safe registered engineers alike, and it applies whether your boiler is brand new or ten years old. A new boiler should have its first service within the first year to keep the warranty intact; an older boiler doesn’t need servicing more often than annually unless it’s showing a fault, in which case you want a repair, not a service.
Is a boiler service a legal requirement?
It depends on who you are. For homeowners, no — there’s no legal duty to service your boiler, though it’s strongly recommended. For landlords, yes in effect — the law requires an annual Gas Safety Check (a CP12) on gas appliances, which is separate from a service. It pays to be precise here, because “service” and “legal check” are not the same thing.
For homeowners
There’s no law that says a homeowner must service their boiler. It’s your choice. That said, skipping it is a false economy: an unserviced boiler is less efficient, more likely to break down, and — crucially — usually falls outside its manufacturer’s warranty, so a failed part you’d otherwise have claimed for becomes a bill you pay yourself.
For landlords
Landlords have a clear legal duty. Under the Gas Safety (Installation and Use) Regulations 1998, you must arrange an annual Gas Safety Check on every gas appliance and flue in the property, carried out by a Gas Safe registered engineer, and provide the tenant with the record (a CP12, or Landlord Gas Safety Record). Importantly, this safety check is not the same as a full service — it confirms appliances are safe, while a service is deeper maintenance. Many landlords have us do both in one visit. If you let property in our area, see our Landlord Gas Safety Certificates page.
Why does an annual service matter?
A yearly service earns its place several times over. It keeps your boiler burning efficiently, so you’re not quietly wasting gas; it dramatically lowers the odds of a cold-snap breakdown, which is when engineers are busiest and waits are longest; it extends the boiler’s working life; and it’s a safety check that can catch a developing fault — including anything that could lead to a carbon monoxide risk — long before it becomes dangerous. In our experience, the boilers that fail in January are almost always the ones that were never looked at.
Does servicing keep my warranty valid?
Yes — in almost all cases. Most boiler manufacturers make a documented annual service a condition of their guarantee, which can run anywhere from two to ten-plus years. Miss a year and you risk a claim being refused on a part that should have been covered. We keep a digital service record for every boiler we look after, so your history is there in black and white, and on new installs we register the warranty for you so it’s sorted from day one.
What happens during a boiler service?
A proper service is more than a quick glance. A Gas Safe engineer will check the boiler is operating safely and efficiently: inspecting the main components and controls, checking the gas pressure and flow, testing the flue for safe emissions, looking for leaks or corrosion, and confirming the system pressure is correct. We’ll clean what needs cleaning, flag anything starting to wear, and leave you with a clear record of the boiler’s health — plus honest advice on anything worth keeping an eye on. No upselling, ever.
How much does a boiler service cost?
Across the UK, an annual boiler service typically costs between £70 and £150 in 2026, according to Checkatrade’s 2026 cost guide and other industry data, with London tending to sit a little above the national average. These are general market figures to help you budget, not a quote — for our price and to book in, see our boiler servicing page, or ask us about a care plan that spreads the cost and keeps you on track each year.
Frequently asked questions
How often should you service your boiler?
Once a year — every 12 months — by a Gas Safe registered engineer. It’s recommended for homeowners and usually required by the manufacturer to keep your warranty valid. New boilers should have their first service within the first year.
Is a boiler service a legal requirement?
Not for homeowners. Landlords, however, must arrange an annual Gas Safety Check (CP12) under the Gas Safety (Installation and Use) Regulations 1998 — a legal safety inspection of gas appliances that is separate from a full boiler service.
What’s the difference between a boiler service and a gas safety check (CP12)?
A CP12 is a legal safety inspection of a property’s gas appliances, required annually for landlords. A service is deeper maintenance that keeps the boiler efficient and the warranty valid. Landlords often arrange both in a single visit.
Does servicing keep my boiler warranty valid?
Usually, yes. Most manufacturers require a documented annual service to keep the guarantee valid. We keep a digital service record for every boiler we maintain, so your warranty stays protected and the history is easy to prove.
How long does a boiler service take?
A standard gas boiler service usually takes around 30 to 60 minutes when the boiler is in good condition. It can take longer if the engineer finds a fault that needs investigating or a part that needs attention.
How much does a boiler service cost?
Across the UK a service typically costs £70 to £150 in 2026, with London tending to sit a little above the national average. These are general market figures, not a quote — see our boiler servicing page for our price.
Are you Gas Safe registered?
Yes. The Happy Heating Co is Gas Safe registered (657972). Every service we carry out is done by a qualified, fully insured domestic gas engineer, with a clear record left for you.
Book your annual boiler service in West London
Due a service, or not sure when your boiler was last looked at? It takes 60 seconds to get booked in.
- WhatsApp us — Book in 60 seconds
- Call 020 8051 2124 — our line is answered 24/7 and we’ll get your details to an engineer
- Book online: boiler servicing
We’re Gas Safe registered (657972) and keep boilers healthy across West and North West London — from Ealing and Chiswick to Kilburn, Queen’s Park and beyond. Heating that just works, no drama.
About the author
Adam Said is a Gas Safe registered domestic gas engineer (657972) at The Happy Heating Co, servicing, installing and repairing boilers in homes across West and North West London. This guide reflects what we see on real jobs every week.
Related reading
- Boiler servicing in West London
- Landlord Gas Safety Certificates (CP12)
- Boiler repairs
- How much does a new boiler cost in West London?
- Areas we cover
Market figures in this guide are typical UK 2026 ranges for budgeting, drawn from current industry cost data (Checkatrade, NimbleFins) — not a quote. Landlord duties are set out in the Gas Safety (Installation and Use) Regulations 1998 (HSE). Verify current figures before relying on them.
