Average Cost to Replace a Boiler

Find out how much it typically costs to install a new boiler, we’ll show you labour charges and how much the boiler itself costs. This price guide was created on 19th May 2016 and was created by a former plumber and heating engineer. The labour costs exclude VAT, that’s because when trading the author was below the VAT threshold.

Don’t forget that this is just one of several price guides. See our full price list here.

Cost Breakdown

Below is a guide price for installing a new condensing boiler to a 2-3 bedroom property:

Cost of Boiler (inc VAT) – £650 (Glow Worm Flexicom includes flue)

Labour for Installing Boiler – £500-£700

Installing/adjusting pipework ~£100 if installing in the same place as the old boiler. £200-400 if you are moving the boiler to a new location.

New central heating control unit – £50 for the unit and £50 for the labour, assuming no additional wiring is required and it’s just a straight swap.

Install radiator valves (thermostatic radiator valves TRV) –  If you don’t already have them then it’s a legal requirement that your boiler installer fits them along with the new boiler. They cost £10-25 each and most plumbers will charge between £10-20 to install each one.

(optional) Have the whole central heating system power flushed. This is recommended if you are having a new boiler installed especially if it hasn’t been done in the last 10 years. See how much power flushing costs by clicking here.

What Can Affect the Price?

In addition to having optional extras such as new controls and a power flush, your choice of who installs the new boiler will also affect the final price.

From speaking to past customers we know that British Gas can charge up to twice as much as a local registered installer. This is because of higher costs for a large business and also because they use salespeople that earn a commission.

Will I Save Money by Installing a Modern Boiler?

Old boilers are inefficient compared to the more modern and newer designs.

An old boiler running at 60% efficiently will cost up to £237 per year more to run when compared to a modern boiler running at 90% efficiency (Source: USwitch)

Also, don’t forget that an older will typically cost more to maintain and repair. Parts may also be more difficult or costly to purchase.

A newer boiler will also make your property more appealing to a buyer and could even increase the value of the property slightly.

How Long Does it Take to Replace a Boiler?

For a straightforward combi boiler swap, the work will take less than one day. If you want an older boiler replaced with a newer combi then allow between 1-1.5 days. If the boiler is being relocated and requires a lot of additional pipework and associated works then expect about 2 days. Having the system power flushed will add about half a day to the job.

When is the Best Time to Replace it?

There is no preferential time but don’t forget that if there are complications with the installation, you could be without gas and hot water for the duration of the work. That might not be much of an issue during the summer but could be during a cold winter.