Fixed-Price Boiler Installation
in Witney, Oxford
& Oxfordshire.
New A-rated boilers installed by Vaillant and Worcester Bosch approved engineers. Up to 10-year manufacturer warranty, fixed price agreed upfront, and a system left cleaner, quieter and more efficient than the day it went in.
Boiler Installation, explained properly.
A boiler installation replaces your existing gas boiler with a modern A-rated appliance (usually a combi, sometimes a system or regular boiler), sized correctly for your home, flushed and pressure-balanced, with new filter, controls and warranty registration.
Homeowners in Oxfordshire whose current boiler is over 10 years old, breaking down repeatedly, no longer meets efficiency requirements, or is under-sized for the way the household actually uses hot water.
When repair costs approach a quarter of replacement, when parts are obsolete, when energy bills climb despite the same usage, or when the boiler no longer keeps up with modern demand (second bathroom, larger radiators, underfloor heating).
A boiler is only as good as the system feeding it. A cheap swap onto a dirty, unbalanced system voids warranties, wrecks pumps and diverter valves inside 12 months, and leaves you paying twice. We size, flush, filter and commission properly, that's what unlocks the 10-year warranty.
The cost of ignoring it.
The wrong installer costs you three times: the wrong boiler, an install that voids warranty, and a system that fails inside two winters.
Voided manufacturer warranty
Vaillant and Worcester both require a magnetic filter, a proper flush and commissioning paperwork. Skip any of them and the 7–10 year warranty becomes 12 months.
Under-sized (or over-sized) boiler
Too small and you get cold showers when two taps run. Too big and you cycle constantly, waste gas and shorten the boiler's life.
Sludge damage to a brand-new boiler
Fitting a new boiler onto a heating system full of magnetite is like putting a new engine into a car with black oil. Pumps and heat exchangers fail fast.
Ongoing high energy bills
A poorly commissioned boiler runs at the wrong flow temperature, wrong pressure and wrong modulation range, costing hundreds a year in wasted gas.
Common mistakes we see
- •Choosing a boiler by output number alone, without a heat loss calculation for the home
- •Reusing the old flue when regulations require replacement
- •Skipping the system flush to save a day and £300
- •Not fitting a magnetic filter (Vaillant / Worcester now effectively require one)
- •Failing to register the warranty within the manufacturer's window
How we run the job.
- 01
Free home survey
We measure the property, count the radiators, check hot water demand, inspect flue routes, gas meter and consumer unit, then recommend the right boiler, not the biggest.
- 02
Fixed-price written quote
One price covering the boiler, filter, flush, flue, controls, warranty registration and commissioning. Klarna finance options included on request.
- 03
Install day
Old boiler removed, new boiler installed with correct flue termination and gas pipework sized to load. Full-system chemical flush and inhibitor dosed.
- 04
Commissioning & handover
Flow temperatures set for your home's heat loss, controls paired, benchmark logbook completed, warranty registered with the manufacturer.
- 05
Aftercare
Annual servicing reminders and priority repair response for the life of the warranty.
What you actually get.
Up to 10-year warranty
Standard 7-year manufacturer warranty on approved installs, extendable to 10 years, priced clearly in your quote.
Lower running costs
A correctly sized, correctly commissioned A-rated boiler routinely cuts gas usage 20–30% versus a tired older unit.
Quieter, more responsive heat
Modern modulating boilers hold flow temperature steady. Radiators warm faster and shower temperature stops swinging.
Klarna finance
Spread the cost of a new install with Klarna. Ask for options in your quote.
One team, one accountability
Same engineers who install come back for the service. No sub-contracting, no finger-pointing.
Clean, tidy install
Old boiler and packaging removed. Floors and worktops covered. Home left as we found it.
Real boiler installation jobs, real Oxfordshire homes.
Depth, not filler.
Boiler installs aren't one product, the right specification depends on the property, the demand and the fuel supply.
Combi boilers
Best for most 1–2 bathroom homes with mains pressure above 1.5 bar. No cylinder needed, instant hot water, compact footprint. We fit Vaillant ecoTEC Plus, Worcester Bosch Greenstar 4000/8000 and Ideal Vogue Max, matched to your gas run and hot water flow rate.
System boilers
Better for larger homes with 2+ bathrooms simultaneously. Runs an unvented or vented cylinder, gives strong, balanced flow to multiple outlets. Common upgrade route from open-vent regular boilers.
Regular / heat-only boilers
The right choice when you already have a hot water cylinder, cold water tank and feed & expansion tank, often a straight swap that avoids re-routing pipework.
Flue arrangements
Horizontal, vertical, plume management kits for boundaries, high-level runs in Cotswold stone properties, building regs and distances from windows/openings are non-negotiable.
Gas supply sizing
Modern boilers demand more gas at peak than older ones. Where the existing 15mm run can't deliver it, we upgrade to 22mm as part of the fixed price.
System protection
Every install includes a full chemical flush, magnetic filter (Adey MagnaClean or Fernox TF1), Fernox F1 inhibitor and, where sensible, a scale reducer for hard-water areas.
Controls & smart heating
Programmable thermostats, wireless controls, Vaillant vSMART, Worcester Wave, Nest, Hive and Honeywell, properly integrated, not just clipped to a wall.
Cotswold stone & listed properties
Flue routing on stone-fronted properties needs care. We work around external aesthetics without compromising regs, talk to us early on listed properties.
Straight answers.
How much does a new boiler cost in Oxfordshire?
Straight combi swaps typically start around £2,000 supplied, installed, flushed and commissioned with warranty registered. Full system upgrades with cylinder work or gas re-runs land higher. You'll always have a fixed written quote before committing.
How long does an install take?
A straight combi-to-combi swap is usually one working day. A conversion (e.g. regular to combi with cylinder removal) is 2–3 days. We'll tell you exactly in your quote.
What warranty do I get?
Standard installs come with a 7-year manufacturer warranty. Extended cover up to 10 years is available on approved Vaillant and Worcester ranges, priced separately in your quote so you decide.
Do you offer finance?
Yes, Klarna is available for boiler installations. We'll walk you through the options when we quote.
Do I really need the flush and filter?
Yes. Manufacturer warranty terms effectively require a system flush and magnetic filter. Skip either and warranty claims can be refused. It's built into every quote we send.
Which boiler brand should I choose?
For most Oxfordshire homes, Vaillant ecoTEC Plus or Worcester Bosch Greenstar are the strongest all-round choice. We're approved on both, so our recommendation is based on your home, not a sales bonus.
Can you handle listed / stone-front properties?
Yes, common across the Cotswolds. We route flues to comply with building regs while respecting the elevation. Talk to us early and we'll survey properly.
What if my boiler dies before you can install?
We prioritise no-heat and no-hot-water calls. If you're waiting on an install we can often provide a temporary fix or fast-track the replacement.
Do you handle the warranty registration?
Yes. We register with the manufacturer on your behalf and provide the benchmark logbook and paperwork you'll need for future service claims.
Related services
All servicesA proper boiler service: stripped, cleaned, tested and recorded, not a five-minute visual check.
Learn moreLocked-out combi, no hot water, weeping seal, fault code you don't understand? Gas Safe registered diagnostics, fixed price in writing, and the parts on the van to finish the vast majority of repairs on the first visit.
Learn moreSystem upgrades, radiator installs, cylinder swaps, chemical cleans and wet underfloor heating designed and installed to work as one system, not a boiler stuck on top of tired pipework.
Learn moreGet a fixed-price quote for boiler installation in Witney, Oxford.
Free, no-obligation quote in writing. Gas Safe, MCS certified where relevant, fully insured to £5m. Local team, real engineers, no call centres.