What’s the Actual Cost of a New Boiler?

In the UK, with our bitter winters and endless desire to enjoy long, hot showers, a good boiler is worth its weight in gold. Unfortunately, they never last forever and eventually it comes time to face the inevitable: replacement.

The problem is that there’s such a wide spectrum of brands, price points, installers and opinions that it’s hard to figure out the actual cost of a new boiler – so let’s find out.

Boilers: Combi or Conventional?

Many prospective buyers assume that combination (or “combi”) boilers are more expensive than their conventional rivals. In fact, if you look at the range of products available from manufacturers like Bosch, Vaillant, Baxi, Glow-Worm and Potterton, they’re about the same.

Either type can cost between £700-£2,700, so the price shouldn’t be the deciding factor when it comes to choosing your boiler type. Instead, look at your energy needs: if they’re high (say running two showers at once) a combi boiler may not have the firepower to handle the demand.


Brand Price Range for a New Combi Boiler Price Range for a New Conventional Boiler
Vaillant £855 – £1,480 £780 – £1,390
Baxi £685 – £1,730 £750 – £1,430
Potterton £610 – £1,300 £575 – £2,640
Worcester Bosch £875 – £2,615 £725 – £2,405


What Determines the Cost of a Boiler?

Clearly there’s a huge range of price points when it comes to boiler shopping. Things like capacity, power rating and the boiler’s newness can all affect the price – let’s look at a few specific models to give a clearer picture.


Brand Type Size Model Average Cost
Baxi Combi 24kW Duo-tec 24 HE A £1,410.00
Worcester Bosch Combi 28kW Greenstar 28i Junior £1,671.60
Vaillant Combi 32kW ecoTEC exclusive 832 £2,181.60
Baxi Conventional 15kW Solo 15 HE A £1,377.60
Worcester Bosch Conventional 18kW Greenstar 18Ri £1,528.80
Vaillant Conventional 38kW ecoTech plus 438 £2,131.20



What catches out many buyer is the installation cost which can, in many cases, double your bill. Hiring a Gas Safe installation engineer is an essential part of the process, since only they can guarantee a safe installation.

Expect to pay in region of £600 – £900 for the installation alone, which will can include:

  • Removing the existing unit
  • Pipework (when installing conventional boilers)
  • Thermostat installation
  • Radiator work

In addition to the regular installation work. Always receive a professional quote (or two, or three) before hiring and make sure you understand exactly how much you’ll be paying before work begins.

Initial vs Long-Term Costs

Replacing a boiler is a substantial investment for most UK homeowners, so it’s important to consider all financial options.

Upfront Payment & Finance

The cheapest way to make any purchase is to pay the entire amount upfront. However, the cheapest way isn’t always the most feasible. If you don’t have £2-3k to spare, then don’t cripple your bank balance over it.

It’s possible to pay as little as £10-20 a month for a new boiler if you purchase it on finance, aka using monthly payments. However, even if you need your boiler replaced ASAP and can’t afford the full payment, try to negotiate for as short a payback period as possible – in the long run, finance schemes could end up costing twice as much money, with agreements lasting anywhere from 5-15 years.

Renting a Boiler

There are schemes which allow you to “rent” a boiler from the service company. You will not be responsible for paying for repairs, and will make a fixed monthly payment for 12 years. Note, this cost will probably rise with inflation! At the end of the 12 years, you will own the boiler, though it will cost you 2-3 times as much as upfront payment.


New Boiler Cheaper Water

New Boiler = Cheaper Water

Based on figures supplied by the Energy Saving Trust, installing a brand-new boiler could provide annual energy bill savings in the region of:

  • £570 – detached house
  • £350 – semi-detached house
  • £290 – detached bungalow
  • £280 – mid-terrace house
  • £145 – mid-floor flat

After 5-10 years of use, assuming no additional repair charges, you will be in profit. While these are averaged figures, they demonstrate the reality out-of-date boilers just burn money. Many over 10-15 years old are running at around 50% efficiency – that’s 50p from every £1 you spend on energy, wasted.

Time to Act?

The reality is that, unless your boiler is old or seriously underperforming, it probably doesn’t need replaced. Some high-quality boilers can outlive their “use-by” dates considerably without a massive decrease in performance.

The easiest way to decide is to have a professional inspect your boiler. Some energy service companies will offer this consultation for free, though you should expect to pay a small amount in most cases. Based on their recommendations, you can decide if it’s time to search for a replacement – only then should you worry about the pricing.

In the end, buying and installing a new boiler upfront will cost anywhere from £1,200 to over £3,000. If you buy on finance or through a rental scheme, you could be facing cost upwards of £7,000 over 12-15 years. The choice is yours.