How to Choose a Boiler Service Company in London: What Actually Matters
Not every boiler service is the same visit under a different name. Here's what to check before you book, and why the paperwork you're given afterwards matters as much as the visit itself.
Start With Gas Safe Registration, Not the Price
Working on gas appliances in the UK is legally restricted to engineers registered with Gas Safe. This isn't a nice-to-have credential to look for among several — it's the baseline. Every gas engineer working on your boiler should be able to show you their Gas Safe ID card, and every reputable firm will say plainly that their engineers are fully Gas Safe registered. If a company is vague about this when you ask directly, that's a reason to look elsewhere before you look at price.
What Should Actually Happen During a Service
A proper annual service follows a checklist, not a five-minute glance. Expect the engineer to inspect the boiler's internal components, check the flue and ventilation, run a combustion analysis, and test the safety devices that shut the boiler down if something goes wrong. Ask what's included before booking — a service that skips the combustion check or the safety device tests isn't doing the full job, even if it's priced the same as one that does.
The Paperwork Is Not an Afterthought
You should leave every service visit with a written record of what was checked. This matters for two practical reasons. First, most manufacturers require an unbroken annual service history to keep a boiler's warranty valid — a missing year of paperwork can be enough to invalidate a claim later, even if the boiler was actually serviced. Second, if you ever sell the property or a fault is disputed, a dated service record is the only evidence that the work happened at all. A company that doesn't automatically hand over a written record after every visit is one to avoid.
Landlords Have an Extra Layer to Check
If you're a landlord, an annual service isn't the only compliance requirement — you also need a current Landlord Gas Safety Certificate (CP12) covering every gas appliance in the property. Ask whether the company can combine the service and the certificate inspection in one visit; it's a common and sensible way to save a second call-out, and many landlords don't realise it's an option until they ask.
A Short Checklist Before You Book
Confirm the engineers are fully Gas Safe registered. Ask exactly what the service checklist covers. Confirm you'll get a written record at the end. If you're a landlord, ask about combining the service with a Gas Safety Certificate. And be wary of anyone quoting a price before knowing your boiler's make and model — a proper quote depends on the appliance, not a flat rate applied to every home in London.
Frequently asked questions
How do I check if an engineer is Gas Safe registered?
Ask to see their Gas Safe ID card, which every registered engineer carries and which shows their licence number and the categories of gas work they're qualified for. You can also check the Gas Safe Register directly using the engineer's licence number.
What should be included in a proper boiler service?
A full inspection of the boiler's internal components, a check of the flue and ventilation, a combustion analysis, and testing of the safety devices that shut the boiler down if a fault develops. You should receive a written record of what was checked at the end of the visit.
Why does the written record from a service matter?
Most manufacturers require an unbroken annual service record to keep a boiler's warranty valid. The written record is also the only evidence a service happened if there's ever a dispute or you sell the property.