New Boiler Installations
A new A-rated boiler from Worcester Bosch, Vaillant or Baxi — expertly fitted by our Gas Safe engineers, with up to a 12-year guarantee and finance from 0%.
Done properly, by a local team
Up to 12-year guarantee
On new Worcester Bosch boilers installed by our team — real long-term peace of mind.
Fixed price, up front
A clear quote after a free survey. What we quote is what you pay — no surprises.
0% & 7.9% finance
Spread the cost with finance options, subject to status, via Novuna.
Combi, system or regular — and what actually decides it
Three boiler types cover almost every Merseyside home, and the choice is settled by hot water rather than by heating. A combi heats water on demand straight off the mains, so there is no cylinder and no loft tank, but it can only give back what the incoming main delivers and it serves one outlet properly at a time. A system boiler works with a pressurised cylinder, usually in an airing cupboard, and runs two showers at once provided the cylinder is sized for it. A regular, or heat-only, boiler keeps the cylinder plus feed and expansion tanks in the loft, and suits open-vented systems and weak mains. As a rough guide: one bathroom and a healthy main points to a combi; two bathrooms, or a household all showering in the same hour, points to a system boiler. Worth knowing — the figure on a combi's badge, 30kW or 35kW, is its hot water output. Its heating output is lower, and how far it modulates down matters more.
What the survey is actually measuring
Four measurements decide whether a quote is realistic. Heat loss: Approved Document L asks that a system is specified from a proper heat loss calculation and not significantly oversized, so we work room by room rather than counting radiators. Gas supply: BS 6891 allows a maximum 1 mbar design pressure drop between the meter outlet and the appliance inlet at full rate, and a 15mm run that comfortably fed a 1990s boiler often will not feed a modern combi, so an upgrade to 22mm is a common and legitimate line on a quote. Flue route: BS 5440-1 sets minimum clearances from windows, doors, boundaries and neighbouring openings — 600mm to a boundary the terminal faces, 300mm where it runs parallel to one, 300mm from an opening — which is where narrow terraces, ginnels and light wells get awkward. Mains flow rate: measured dynamically at the kitchen tap, with the water running, not read off a static pressure gauge. As a working rule of thumb rather than a standard, below about 12 litres a minute a combi tends to disappoint whatever its badge says; 15 to 20 gives a shower most people are happy with. A good surveyor measures rather than assumes.
What a fitted price covers
Our combi swaps run from £2,000 to £2,850 fitted, and the spread reflects the boiler, the flue route and how much pipework has to change, not a sales grade. Whoever you ask, a fitted price ought to cover the boiler and its standard flue, removal and disposal of the old appliance, a filter, a chemical clean and flush, inhibitor, the controls Part L requires, the condensate run, gas tightness and working pressure checks, commissioning, guarantee registration and notification to Building Control. Ask any installer to confirm each of those in writing, because that is where cheap quotes are cheap — and your written quote from us itemises exactly what is and is not included for your job before you commit to anything. Work that is genuinely extra, and should be priced before we start rather than found on the day: new radiators, replacing tired pipework, upgrading the gas run from the meter, moving the boiler to another room, scaffolding for a high flue, and making good plaster or tiling beyond a patch.
Installation day, start to finish
A straight swap in the same position is usually a one-day job. A conversion, a relocation or a back boiler removal is two to three days. We isolate gas, water and electrics, drain the system, take the old appliance out, then run new gas, condensate and heating pipework before the boiler goes on the wall. Condensate goes to an internal drain wherever possible; where it has to run outside it goes in 32mm, insulated and kept short. The system is then chemically cleaned and flushed, a permanent in-line filter fitted and inhibitor added — Approved Document L requires the clean, the flush, the inhibitor and commissioning to BS 7593, and the permanent in-line filter is BS 7593:2019's own requirement rather than a Building Regulations one. Commissioning is the part that cannot be rushed: a gas tightness test, working pressure at the appliance, a flue gas analysis with a calibrated analyser, and the Benchmark checklist left with you. Expect no heating or hot water for most of the day. We need access to the boiler, somewhere to run a hose and parking nearby. Floors get covered, and the old boiler leaves with us.
Back boilers and fireplace conversions
Plenty of Merseyside semis and terraces still run a back boiler behind a gas fire in the chimney breast — Baxi Bermudas especially. Most are non-condensing, parts have all but disappeared, and no back boiler is made for the UK market any more — a non-condensing replacement could not meet Part L's 92% ErP minimum — so replacement means conversion rather than swap. The fire and the unit come out of the builder's opening, the old flue arrangement is dealt with, the chimney is capped or terminated correctly, and the new boiler goes somewhere sensible: kitchen, utility or airing cupboard. That brings new gas, a new condensate route, fresh flow and return pipework across the house, and making good where the fireplace was. A decommissioned back boiler should be drained down and its gas supply capped, and removed where access allows — leaving a sealed unit full of water behind a working fire is not something we are willing to do. These jobs are quoted individually and sit above the standard swap range.
Merseyside housing stock, and what it changes
We cover 209 towns and districts, and the housing stock changes what a boiler job involves from one street to the next. Victorian terraces across Kensington, Bootle and Toxteth are solid nine-inch brick with no cavity to fill, so a terrace can lose considerably more heat than a cavity-walled semi of the same floor area. Undersize on heat loss and the house never quite gets there in January. Flue clearance to the neighbouring boundary over a shared ginnel is the other recurring problem. The 1930s semis of Childwall, Allerton and the Wirral bring back boilers, chimney breast pipework and, in 1980s refits, microbore that needs checking before a low flow temperature is discussed. Converted flats in Aigburth, Waterloo and Wallasey have their own list: shared gas risers, flue terminations over a light well, upper-floor mains pressure that reads fine downstairs and poorly at the top, and freeholder consent for a new flue penetration. In flats built since about 2000, a flue running through a ceiling void needs inspection hatches — or an approved CO void monitoring safety shut-off system — before an engineer can sign it off; with neither, Gas Safe guidance has it classified At Risk. Local mains water averages soft to slightly hard, so sludge worries us more than scale, though hardness does vary noticeably by postcode.
Controls, guarantees and the paperwork you keep
A replacement gas boiler in England should be at least 92% ErP — the minimum set out in Table 6.2 of Approved Document L, which allows a lower SEDBUK figure only in narrowly defined exceptional circumstances. Where a combi goes into an existing home, Part L requires one further efficiency measure — flue gas heat recovery, weather compensation, load compensation, or a smart thermostat with automation and optimisation — and when a boiler is replaced, every room should get thermostatic room control, with the room holding the thermostat left without a TRV on its radiator so the two do not fight each other. Where a system is fully replaced, radiators and pipework included, it should be sized to run at 55°C or lower; on a boiler-only swap that is not always achievable, so we set the flow temperature as low as your existing radiators will carry. As a Worcester Bosch Accredited Installer we can offer up to a 12-year guarantee on eligible Worcester models. The 12-year term is on the Greenstar 8000 range; models below it carry less, and the Greenstar 1000 at the bottom of our range carries five years. Every extended term is subject to a qualifying Greenstar System Filter being fitted at installation — the System Filter Micro does not qualify — registration within 30 days and an annual service. Other brands vary and we confirm the term in writing. We notify Gas Safe, and your Building Regulations Compliance Certificate follows by post, usually ten to fifteen working days after notification.
Simple, from quote to comfort
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Free survey & fixed quote
We visit, assess your home and give a clear fixed price — no pressure, no jargon.
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Pick a date that suits you
Choose a day that works. We confirm everything up front and answer any questions.
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Tidy, Gas Safe install
Our engineers fit your system cleanly and safely — and leave your home spotless.
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Aftercare & guarantee
You're covered by the manufacturer guarantee, with our local team a phone call away.
Related services
Our happy customers
Real Merseyside homeowners on their new boiler — filmed after the job's done.
Common questions
How long will I be without heating and hot water?
For a straight combi swap in the same position, most of one working day. We arrive early and have the system refilled, commissioned and running by late afternoon. Conversions, relocations and back boiler removals take two to three days, and we tell you beforehand which days you will be without hot water. If someone in the house is vulnerable to cold, say so when you book and we will plan around it.
Will a combi give us enough hot water for two bathrooms?
Usually not at the same time. A combi heats water as it flows, so two showers running together halve what each gets. If both are genuinely used at once, a system boiler with a correctly sized cylinder is the better answer. If the second bathroom is occasional, a combi with a strong flow rate is often fine. We measure this at survey, because the answer depends on your incoming main.
Do my radiators and pipework need replacing too?
Not usually, but they do need checking. We test the system, chemically clean and flush it, then fit a filter and inhibitor before the new boiler runs. Microbore pipework, common in later refits, limits how low we can run the flow temperature, and radiators sized for a 1980s system may be small for efficient low-temperature running. Where a radiator is corroded or a valve seized, we price it at survey rather than discover it mid-install.
What guarantee do I get with the boiler?
It depends on the boiler. As a Worcester Bosch Accredited Installer we can offer up to a 12-year guarantee on Worcester models — that longest term is on the Greenstar 8000 range, and models below it carry less, so we confirm your boiler's exact term in writing with the quote. Every Worcester term requires a qualifying Greenstar System Filter fitted at installation (the System Filter Micro does not qualify), registration within 30 days and a service every year of the term. Other manufacturers set their own lengths. Miss a service and a manufacturer can shorten or refuse the guarantee, so keep the records.
Is there a grant towards a new gas boiler?
Not for most households. The Boiler Upgrade Scheme funds heat pumps rather than gas boilers, and that grant is claimed through an MCS-certified installer. Help towards a replacement gas boiler is means-tested, delivered through council and energy supplier schemes whose rules and closing dates change regularly. Start with your council's home energy team or GOV.UK to check current eligibility, and we can work alongside whatever scheme you qualify for.
Can I spread the cost?
Finance is available on new boiler installations, subject to status. We do not quote a rate on this page — our finance page sets out how it works, and your written quote shows the exact monthly figure for the boiler you choose. There is no obligation to take finance to get a quote.
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Free, no-pressure quote from a local Gas Safe team — with 0% and 7.9% finance available.