DATA-BACKED GUIDE · UPDATED JULY 2026
New boiler installation cost: labour and fitting prices in the UK
The price of the boiler on the shelf is only half the story, because the labour to fit it can rival the cost of the unit itself. A straight swap in the same spot is a day's work, while moving the boiler or upgrading old pipework turns it into a bigger job spread over two or more days. The real prices below separate the fitting from the box, so you can see what installers actually charge to get a new boiler up and running rather than a headline figure that hides what's included.
The quick version
- The install bill covers the engineer's labour, sundries, flushing the system and testing, not just fitting the box.
- A like-for-like swap in the same position is the cheapest job, while relocating the boiler adds a day or more to the work.
- A new gas boiler is standard work, so it carries 20% VAT rather than the reduced rate for energy-saving measures.
- Any gas boiler must be fitted by a Gas Safe registered engineer, which protects both you and the warranty.
- National firms and local independent engineers can quote very differently for the same job, so it pays to get both types of quote before you commit.
- Where you live changes the price too, with London rates sitting above much of the rest of the country for identical work.
What people actually paid
Real prices, in people's own words
- £2,000“a 30kw one at a cost of £2k January 2021”
- £2,000“£2k”
- £2,400“I recently had a Worcester boiler installed (no other work, just a new boiler) and that was £2400 on it's own (including VAT and labour).”
- £2,500“just paid 2500 for a new combi (similar cost boiler)”
- £2,500“just paid 2500 for a new combi”
- £3,500“We paid £3500 to have a new boiler fitted and the old back boiler removed for my mum”
Genuine amounts posted publicly. We publish the price and the quote, never the person.
Why the price varies so much
What looks like the same job on paper can carry very different labour costs. The simplest and cheapest scenario is swapping a combi for a combi in the same place, where the pipes already line up and the engineer isn't fighting the existing layout. The moment you move the boiler to a new wall, convert from a system boiler to a combi, or run a new gas supply and flue, the hours climb and so does the price. Older homes often need a power flush to clear sludge from the radiators before a new boiler is connected, which adds a chunk of time on its own. Access matters too, as a loft or awkward cupboard install is slower and more fiddly than one at waist height in an open utility room. Who you book also shapes the bill. A national firm carries call centre costs, marketing and a sales layer on top of the engineer's time, while a local independent Gas Safe engineer working out of a van has lower overheads and often prices closer to the actual labour involved. Location plays a part too, with London rates sitting above much of the rest of the country, so the same combi swap can cost noticeably more depending on where in the UK you live.
How to pay less
- Keep the new boiler in the same spot if you can, since relocating it is one of the biggest labour add-ons.
- Get three quotes from local Gas Safe engineers as well as any national firm, then compare like for like on labour, parts and warranty.
- Ask whether a power flush is genuinely needed or whether a cheaper chemical flush will do the job on a system that isn't badly sludged.
- Pay on a credit card where possible so Section 75 protection covers you if the installer disappears before the job is finished.
- Book outside the depths of winter if you can, since engineers are less rushed off their feet in a July heatwave than in a January cold snap.
- Ask each quote to itemise labour separately from the boiler and controls, so you can see exactly what the fitting is costing you.
Common questions
Why does fitting a boiler cost so much on top of the unit?
You are paying for a Gas Safe engineer's day or two of skilled labour, plus fittings, flushing the system, the flue, controls and testing. On a straightforward swap the labour is lower, but any pipework changes or a relocation push it up, as the real prices below show.
Is it cheaper to keep the boiler in the same place?
Yes, usually much cheaper. A like-for-like swap where the pipes and flue already exist is the quickest job. Moving the boiler means new pipe runs, a new flue and more hours, so it is the single biggest thing that lifts an install quote.
Do I pay VAT on a new boiler?
A standard gas boiler is normal-rated work, so 20% VAT applies to the supply and fit. The 0% rate is for energy-saving measures like heat pumps and insulation until 2027, not for a conventional boiler replacement.
Is a national installer or a local engineer cheaper?
It varies job by job, but a national firm generally carries more overhead in call centres and sales staff than a local Gas Safe engineer working alone or in a small team. Getting quotes from both for the same specification is the only way to see which works out cheaper for your particular job, since a national firm's warranty package can sometimes offset a higher price.
Do I need a power flush every time I replace a boiler?
Not always. A power flush clears sludge and debris from old radiators and pipework so the new boiler isn't damaged by dirty water, and it's genuinely worth it on an older system that has never been flushed. On a newer system, or one flushed recently, a cheaper chemical flush is often enough, so ask the engineer to justify the recommendation rather than accepting it as standard.
Does where I live in the UK change what I'll pay for installation?
Yes. Labour rates in London and the South East tend to run above the rest of the country, so the same swap of a combi boiler can cost more there than in other regions. Getting local quotes rather than relying on a national average is the only reliable way to know what installation costs where you actually live.