DATA-BACKED GUIDE · UPDATED JULY 2026
New boiler cost in the UK: combi vs system prices
Swapping out a tired boiler is one of those jobs most of us only do once a decade, so it is hard to know what a fair figure looks like. The right price depends on the type of boiler, the make, and how much pipework needs changing. The real prices below come from actual prices, so you can see what people paid rather than a sales quote.
The quick version
- A combi boiler tends to cost less to fit than a system boiler because it needs no separate cylinder or tank.
- The boiler unit itself is only part of the bill; labour, flue, controls and any pipework changes add up too.
- Moving the boiler to a new spot, or converting from one type to another, pushes the price up.
- A quality new boiler with a long warranty often works out cheaper over its life than the cheapest option.
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
No two boiler jobs are identical, which is why quotes bounce around so much. A straight like-for-like combi boiler swap in the same location is the quickest and cheapest scenario. Once you add a hot water cylinder for a system boiler, extra radiators, a new flue run, or a chemical flush of a sludgy system, the labour and parts climb. Brand matters as well; premium makes with a decade-long warranty sit above budget units. Where you live plays a part too, and a national firm usually quotes above a good local installer for the very same work.
How to pay less
- Get three written quotes from Gas Safe registered local installers and compare like for like.
- Ask whether a like-for-like combi boiler swap is possible before agreeing to any relocation or conversion.
- Check what the warranty covers and how long it lasts, since a longer warranty can save you later.
- Book outside the autumn rush, as engineers are often keener on price in spring and summer.
Common questions
Is a combi or system boiler cheaper to install?
A combi boiler is usually cheaper to fit because it heats water on demand and needs no separate cylinder or loft tank. A system boiler suits homes with high hot water demand and several bathrooms, but the extra cylinder and pipework add to the cost. Check the real prices below to compare both.
How long does a new boiler take to fit?
A straightforward like-for-like swap is often done in a day. A conversion from one boiler type to another, or moving the unit to a different room, can take two to three days because of the extra pipework and making good afterwards.
Do I need a Gas Safe engineer?
Yes. Any gas boiler work must be carried out by a Gas Safe registered engineer by law. Always ask to see the card and check the registration before work starts, and keep the paperwork for your warranty and any future sale.