Trades guideHeating service
New boiler install: a local engineer and a warranty that holds
A new boiler install replaces the boiler and, done properly, includes a magnetic filter, a system flush, an inhibitor dose and a benchmark commissioning certificate, all of which protect the warranty. Using a manufacturer-accredited installer unlocks the longer warranty. We read your enquiry and reply by email; we do not pass your enquiry to a trade.
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What a proper install includes
- The boiler, sized to your home and hot-water demand.
- A magnetic filter, now required by the major makes for the long warranty.
- A system flush, a powerflush on an existing system or a chemical flush on new pipework.
- An approved inhibitor dose, logged on the benchmark certificate.
- The benchmark commissioning record and Gas Safe notification.
The accredited-installer warranty
Manufacturer-accredited installer schemes unlock an extended warranty beyond the standard term. The premium over a non-accredited install is usually modest, and the extra years of cover are normally worth it on an appliance you keep for a decade. Confirm the scheme in writing.
Choosing the right boiler type
A combi suits one to two-bathroom homes; a system boiler suits more bathrooms or simultaneous demand and is the more heat-pump-compatible layout. The boiler brand affects the maximum warranty but matters less than a correct install.
What it costs
- New boiler install
- Get a quote (all-in) Ask for the filter, flush, inhibitor, benchmark and notification to be listed as included.
- Off-peak timing
- Often cheaper Late spring to summer is the cheaper window for a planned combi swap.
For the cheapest time to replace and the four non-negotiables, see the related guides.
How to choose a trade
- Use a Gas Safe registered engineer, and a manufacturer-accredited installer for the extended warranty.
- Check the quote lists the magnetic filter, the flush, the inhibitor dose and the benchmark certificate as included.
- Get the install evidence photographed and the manufacturer registration completed on the day.
Frequently asked questions
What should a new boiler install include?
The boiler sized to your home, a magnetic filter, a system flush, an approved inhibitor dose, and the benchmark commissioning certificate with Gas Safe notification. These protect the warranty. A quote that omits the filter or the flush is cutting a corner that can void the manufacturer cover.
Does the installer affect my boiler warranty?
Yes. Manufacturer-accredited installer schemes unlock a longer warranty than a Gas Safe but non-accredited install, which often reverts to the statutory minimum. The premium for an accredited installer is usually modest and worth it for the extra years of cover on an appliance you keep for a decade.
When is the cheapest time to install a new boiler?
Late spring to summer for a planned combi swap, when manufacturer cashback and slack installer diaries lower the price and there is no winter emergency premium. If your boiler is failing now, do not gamble on it surviving winter, as an emergency swap costs more in any month.
Sources
Editor, VettedHome
Adam leads VettedHome's editorial coverage of UK home services. He is the founder and managing director of Muswell Rose, the commercial strategy and modern systems business behind a portfolio of UK information sites, and he researches and writes the plain-English guides that help homeowners choose between installers and trades, drawing on the standards set by the relevant bodies for each job, such as Gas Safe Register, NICEIC, MCS, TrustMark and the Property Care Association. He is clear about what to check before any work starts.
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