5-year warranties
Common baseline. Usually easier to qualify for, fewer “extras” required — but you still need a correct install and annual servicing.
Best for: straightforward swaps where budget matters but you still want it done properly.
Boiler warranties: 5 vs 10 vs 12 years
and the stuff that quietly voids them
Boiler warranty length is one of those things people only care about once they’ve had a bad experience. Usually it goes like this: you pay for a “10 year warranty boiler”, you relax… then year three something fails, and suddenly there’s paperwork, terms, and an awkward sentence that starts with “unfortunately…”.
We fit and troubleshoot boilers across London (we’re based in East London, E7). We’ve seen warranties honoured quickly, and we’ve seen them refused for reasons that feel petty until you realise the manufacturer is protecting itself. If you want a warranty-safe installation done properly, call +44 7727 154 746.
Warranty-safe installs
Worcester • Vaillant • Ideal
London homes & flats
For the full install process (survey → protection → commissioning), start here: boiler installation done properly.
The quick truth about boiler warranty length
Longer warranty doesn’t automatically mean “better boiler”. It often means “better package”: correct installer accreditation, the right controls, proper commissioning, and proof the system is protected. Miss one of those and the “12 year boiler warranty” can shrink fast.
10-year warranties
The sweet spot for many London homeowners. Often tied to accredited installers and certain components being included.
Watch for: “must be installed by X-level installer” + proof of protection/cleanliness.12-year warranties
Typically the “max” package: specific boiler ranges, specific controls, sometimes specific filters, plus registration deadlines.
Worth it when: you’re staying put and you want the boiler to be a boring non-issue for a decade.If you’re comparing brands mainly on warranty, start here: Worcester vs Vaillant vs Ideal comparison.
A real warranty moment (the one people don’t expect)
We had a call not long ago from a homeowner who genuinely thought the manufacturer had made a mistake. “It’s got a 10 year warranty,” they said, “so why are they refusing to send parts?” When we looked into it, the boiler was registered late and the system protection wasn’t recorded properly. Nothing outrageous had happened — it was more like death by small admin.
The frustrating bit is the boiler itself was fine quality. The problem was the paper trail and the install standards. That’s why we’re picky about doing the unglamorous stuff: correct sizing, clean system water, filter/inhibitor, proper flue/condensate routing, and commissioning settings that make sense.
If you want a no-drama install quote that includes the “warranty-safe” steps, these pages help: installed boiler price ranges and why quotes vary so much.
What voids boiler warranties (the common London ones)
Every manufacturer’s wording is slightly different, but the reasons for refused claims are weirdly consistent. Here are the ones we see most — and how to avoid them without turning your boiler install into a science project.
Skipping protection (filter/inhibitor) on a dirty system
Sludge and debris shorten boiler life. Manufacturers know it, so they look for evidence the system was protected. If you want the plain-English version, read magnetic filter + inhibitor basics.
Tip: even if the system “seems fine”, older London pipework can hide muck until the new boiler starts circulating harder.No proper system clean where it’s clearly needed
Not every install needs a full power flush, but some absolutely do. This is why we assess it instead of guessing. See do you actually need a power flush?
Think: cold radiators, black water, noisy pump, repeated pinhole leaks — those are clues.Flue/condensate issues
Flue safety isn’t optional. If a flue is incorrect, the manufacturer can (and should) refuse to back it. If you want the London-specific rundown: flue and condensate rules explained.
Seen it a lot in conversions and tight side returns where “there’s nowhere else to put it”. There usually is — it just needs planning.Wrong sizing or poor commissioning
Oversizing isn’t “safe”. It can cause short-cycling and inefficiency, and it’s often the hidden reason people complain their new boiler feels worse. We cover that here: choosing the right boiler size.
Commissioning matters: flow temps, gas pressures, system balancing — boring details, big outcome.Late warranty registration / missing paperwork
This one catches people out. Some warranties require registration within a set time after install and proof of an annual service. We register where required and make sure you know what to keep.
Small admin job on day one. Big difference in year four.Servicing missed (or done poorly)
Most long warranties assume an annual service. Miss it, and it gives the manufacturer an easy exit. It’s annoying, but it’s the game.
If you’re the type to forget, put the service month in your calendar the day the boiler goes in.And if you’re thinking “how long is the house going to be without heating while this happens?”: how long a boiler install takes.
Want a warranty-safe quote (without the sales chat)?
Call +44 7727 154 746. If you’re near Forest Gate / Stratford and you can send a quick photo of the boiler location + the outside wall where the flue exits, we can usually tell you what’s involved pretty fast.
Call now — talk it through
Prefer message? send photos for a warranty-safe quote and we’ll reply with a clear plan (no fluff).
What people remember after the install
People rarely leave reviews because the boiler is “nice”. They leave them because the experience felt calm: punctual, tidy, problem understood quickly, job finished properly.
“My boiler went wrong, Abdul and his team came and fitted a new one… they worked without taking a break, cleaned up when…”
Alison Louis“Excellent plumbing service! Always punctual, professional, and true to their quote — highly recommended!”
Elimelech Halberstam“Great service prompt and efficient. Fitted a new boiler… took away old boiler and all other waste… would definitely recommend.”
Grant Hodges (Local Guide)If you want the “full install” hub this page supports, it’s here: boiler installation done properly.
Boiler warranty questions (different answers for different homes)
Is a 12-year boiler warranty always worth paying more for?
Not always. If you’re likely to move in a couple of years, a strong 5–10 year warranty can be plenty. If you’re staying put and you want maximum peace of mind, 12 years can be a good deal — as long as the install qualifies for it and you keep up servicing.
What’s the most common reason a warranty claim gets refused?
Missing servicing records is the big one. After that: lack of system protection (filter/inhibitor) and install issues that should have been corrected at day one. It’s boring stuff, but manufacturers use it as a clear line in the sand.
Do I need a power flush to keep the warranty valid?
Not universally. Some systems need it, some don’t. The key is that the system is clean enough and protected properly. We explain it here in plain English: do you actually need a power flush?
If I buy a boiler online, will the warranty still apply?
Often it can, but it still depends on correct installation, registration, and servicing. Also: the boiler must be suitable for the property and system. If you want to sanity-check a model before you click “buy”, call us — it’s a five-minute conversation that can save you a headache.
How do I maximise my warranty from day one?
Get the boiler sized correctly, clean/protect the system (filter + inhibitor), make sure flue/condensate routes are correct, register the warranty on time, then service it annually. That’s the recipe.