New Combi Boiler Installation Costs in the UK: A 2026 Guide

If you are pricing up a new combi boiler, you will find quotes ranging from under two thousand pounds to well over four, often for what sounds like the same job. This guide explains what sits behind those numbers, using realistic figures for homes in Burnley and the wider Lancashire area, so you can judge whether a quote is fair before you sign anything.

Published 17 August 2026

Typical price ranges for a combi boiler installation

For a straightforward like for like swap, where your old combi comes off the wall and a new one goes in the same spot, most UK households pay somewhere between £1,800 and £2,800 fully installed. That figure includes the boiler itself, a new flue, a magnetic filter, a chemical clean of the system and the labour, which is usually one day of work.

If you are converting from an older heat only or system boiler with a hot water cylinder and tanks in the loft, expect £2,700 to £3,800 or more. The extra cost covers new pipework, removing the cylinder and tanks, capping off redundant pipe runs and often a second day on site. Moving the boiler to a different room, for example from an airing cupboard to the kitchen, adds pipework and flue costs on top.

What actually drives the price up or down

The boiler itself is only part of the bill. A reliable mid range combi suitable for a typical two or three bedroom terrace or semi costs the installer £700 to £1,200, while premium models with longer guarantees can be £1,500 or more. The rest of your quote is labour, materials and the state of your existing system.

Older properties around East Lancashire often throw up extras that a quote over the phone cannot see. Common ones include upgrading the gas supply pipe to meet current regulations, replacing corroded radiator valves, fitting a condensate pipe where none exists, and dealing with sludged up pipework that needs a powerflush, which typically adds £300 to £500. A good installer will survey the property first and put these items in writing rather than surprising you on the day.

Choosing the right size and spec, not just the cheapest

Combi boilers are sized mainly on hot water demand, not the number of radiators. A 24 to 30kW model suits most two and three bedroom homes with one bathroom, while a house with two showers in regular use may need 35kW or above. An oversized boiler costs more to buy and can cycle inefficiently, so bigger is not automatically better.

Guarantee length is worth weighing against price. Many mid range boilers now carry 7 to 10 year manufacturer guarantees when fitted by an accredited installer, but these usually depend on an annual service, so factor £80 to £100 a year into your running costs. A smart or weather compensating control, often £100 to £250 fitted, can trim gas bills and is required to meet Boiler Plus rules in England when certain controls are replaced.

How to get a quote you can trust

Always insist on a home survey before accepting a price. The installer should check your gas pipe size, water pressure and flow rate, flue route and radiator condition, then give you a written quote itemising the boiler model, controls, filter, flush and any remedial work. If two quotes differ by hundreds of pounds, the itemised lists will usually show you why.

Whoever you use must be on the Gas Safe Register, and you can check their number free at gassaferegister.co.uk before they start. In Burnley and surrounding towns such as Padiham, Nelson and Accrington, a local firm can usually survey within a few days, and using someone nearby makes life easier if you ever need a callback under guarantee.

Common Questions

How long does a combi boiler installation take?
A like for like swap is normally done in a single day, with heating and hot water back on that evening. Converting from a cylinder system or moving the boiler to a new location usually takes two days.
Is it worth paying more for a premium boiler brand?
Often yes, if the longer guarantee matters to you, since 10 or 12 years of cover can outlast a cheaper boiler entirely. That said, well fitted mid range boilers on a clean, properly flushed system are reliable, and installation quality affects lifespan as much as the badge on the front.
Can I spread the cost of a new boiler?
Many installers offer finance, and some homeowners use a bank loan or credit card instead, which can work out cheaper than installer finance once interest is compared. If your boiler is broken rather than just old, ask about interest free periods, and always check the total repayable, not just the monthly figure.

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