Complete our form and receive free quotes within minutes: Request FREE Quotes

How much does a Boiler Replacement cost?

boiler cost

As your existing boiler ages and begins to fail, you need to start researching replacement boilers. It is important not to fall into the trap of assuming the same sort of boiler is the best replacement option for you. Boiler technology is constantly improving and regulations are also now in force to ensure most new boilers are as efficient as possible. Almost all new boiler installations must be condensing boilers, which are estimated to be around 25% more efficient than non-condensing boilers. This lowers your energy bills in turn. In very occasional circumstances, it is impossible to safely position a condensing boiler, or a similar problem exists. Only under these circumstances are non-condensing boilers permitted to be fitted, and a certificate to this effect must be issued by an engineer prior to the boiler replacement.


The first decision to be made is the type of boiler you need for your lifestyle and it follows that the costs vary according to the make and the kilowatt output. The models suggested below are intended to give an indication of costs. The prices are current at time of writing but should be confirmed with the vendor.


Combination boilers (commonly known as combi boilers)

These boilers contain a small hot water tank within the boiler casing but otherwise can provide heat and hot water on demand. However, pressure does drop when more than one tap is used at any one  time in the house. There is no need for a separate cylinder or water tank in the loft. Combi boilers can be more complicated than others types to fit, and the installation costs will reflect this. Suggested models include:

  • Intergas Combi HRE Boiler 24/18 - £669.99  VAT. This unit is fuelled by gas and has low maintenance costs
  • Firebird Environmax Combi C20 - £1503.12  VAT. Oil fired boiler
  • Glow-Worm Flexicom 35CX Combi Boiler - £741.67  VAT. Gas powered, with small case size, fitting into a standard kitchen cupboard
  • Worcester Greenstar Heatslave II 12/18 External Oil Combi Boiler - £2114.81 including VAT. Oil fired boiler suitable for external installation
  • Heatrae Sadia Electromax 9kw Electric Heating Boiler & Store - £1274.69  VAT

System boilers (also known as sealed system)

Sealed system boilers have a hot water cylinder but no water tank in the loft. You get hot water at normal pressure from multiple taps. However there is a delay on getting hot water to the taps, and it can run out, with a lengthy wait while the water is heated up again. System boilers are suitable for situations where more than one hot water tap will be running at a time. A selection of models include:

  • Biasi Riva Plus 24 System Gas Boiler (including Standard Horizontal Flue) - £570.00 including VAT. Fuelled by gas with electronic ignition. Very compact design suitable for small spaces.
  • Thermeco 12/24 external condensing system boiler - £2011.36 including VAT. Oil fired boiler suitable for external placement.
  • Elnur CM15 Electric System boiler 15kw - £799  VAT. Unlike gas or oil boilers, this electric boiler does not need yearly maintenance.

Traditional boilers (otherwise known as conventional or vented system boilers)

Traditional boilers have both a hot water cylinder and a water tank in the loft. Hot water is quickly available from multiple taps, but the amount is limited to the volume of the cylinder. Once it has run out, no hot water is available until the cylinder has reheated. Some models worth researching further would include:

  • Alpha CD13R Condensing Conventional Gas Boiler - £615.17 including VAT. Highly efficient condensing boiler, using gas fuel and can be converted into a system boiler with the purchase of an additional kit.
  • Vaillant EcoTec Plus 438 High Efficiency Condensing Conventional Boiler - £1179.17  VAT. Gas powered and available in different sizes to suit different sized properties.
  • Worcester Greenstar Camray Utility 12/18 Regular Oil Boiler - £1136.60 including VAT. Claiming to have 93% efficiency, this oil fired boiler is available in different capacities.
  • Trianco Contractor 100/125 HE External Oil Heating Boiler - £1118.98  VAT. Oil fired, and suitable for outdoor placement.


There are four main different fuel options. Gas, oil, LPG or Electric. Gas boilers are the most common, with approximately 69% of homes utilising gas power. The purchase price of a gas boiler reflects their popularity as the price is generally cheaper than equivalent oil boilers. Unless you do not have gas available to you, it is usually the preferred option as the annual cost for an average home is £650 to 700 per year.

Oil boilers are generally the most popular among the 4 million UK households who are not connected to mains gas. The purchase price of the unit is at a premium rate, and the running costs for an average size house is between £1100 and £1400 per annum.

LPG (Liquid Petroleum Gas) retains only a small market share in the boiler industry. While it is efficient and has the lowest carbon footprint of all the fuels, the cost of LPG is rapidly increasing. The annual cost for an average house is likely to be between £1300 and £1600.

Electrically powered boilers are relatively new in the market. The purchase of an electric boiler is comparative to a gas boiler making the initial investment attractive. Annual costs for an average house are around £1300 to £1600 per annum.

The Green Deal

Your old boiler is likely to be extremely inefficient. The Green Deal is a government incentive to scrap the old inefficient boilers still in existence, replacing them with new efficient boilers with a lower carbon footprint. This can save you an estimated £300 per year. The Green Deal is a government loan for the cost of a new boiler, with the repayments being added to utility bills over 25 years. The higher efficiency of the new boiler usually more than covers the repayments.


The law says that if you install a new gas boiler you have to notify the authority.

Normally you don´t need a planning permission for installation or replacement of a boiler but  there is an exception, in case if you live in a listed building you should check your Local Planning Authority and check the special regulations.

If the installation of your boiler requires a flue to be fitted outside, in this case there is the possibility you may require planning permission, except the conditions below are accomplished.

Boiler replacement rules and regulations
  • Is it admissible one meter above the main part of the roof to have flues on the rear or side elevation of the construction.
  • Our advice is to be in touch with your local planning authority before a flue is fitted if the construction is listed.
  • Another thing is to protect the conservation areas, World Heritage sites, areas of natural beauty and not fitting the flue on the principal if it fronts a highway.

If a heating system or hot water system is to be replaced then an application may not be required, and, if it is required, it may not be necessary to apply in advance of carrying out the work.

 You have to be sure that you use a qualified engineer if you want to install a new boiler.


To replace a boiler takes one day. If you have a combi boiler this means two visits. A boiler may need basic maintenance, emergency replacement, fixing the radiators, repair water leaks etc., but the most important is to find a solution for these problems, and the solution is the right home improvement company.

If your boiler is old we suggest you consider a replacing your boiler with a new one.

Old boilers can pose danger because and there is a risk to be exposed to dangerous emissions such as a carbon dioxide and carbon monoxide.

Boiler replacement

We are helping you to find the perfect installer that suits to your budget, home and the benefits are not only just that the efficiency of your central heating is increasing but will reduce your heating bills too

For us is important to have your postal code and a description of the project, and we will send at least four tradespeople with no obligation and no fee.

Your local heating engineer should be able to carry out the work for you and with our help you will have an experienced heating engineer who will take a look at your existing boiler. The engineer will make a number of tests on the boiler and this will depend in part on the fuel and boiler.

He will discuss your options and provide you with a quote. To be sure we suggest you to get three quotes more so you can get a competitive price.


The boiler is an important item in your home and for this it is important to have it serviced constantly.

You should have your boiler serviced at least one a year and the best period to this is in the summer but however if you noticed a deterioration of the boiler you have to contact with a plumber to check out your boiler.

A clear example of the benefits of having a boiler service is for example, servicing a kerosene boiler, which has not been serviced for 3 years, will bring about an instant fuel diminution of some 5%.

The main advantages

  • A serviced boiler can improve efficacy of your  boiler up to 15 %
  • Protect your health! Boilers that aren´t checked can produce carbon monoxide.  You have to test and to prevent carbon monoxide poisoning. Symptoms of carbon monoxide poisoning include stomach pains, headaches etc. Carbon monoxide can´t be seen or smelt so check your boiler regularly.
  • Having your boiler serviced keeps your boiler warranty or extended warranty valid
  • By having your boiler serviced each year by a qualified professional you can extend its lifespan for many more years than if you don’t and you can also avoid irrelevant failures which can also result to be costly to fix.

A boiler is the heart of every home, even more so in winters so it is essential to have the right professionals for annual boiler servicing. You can find untrained service people, who may be charging less money than the competition but might not deliver the best service.


Having an efficient boiler can make a big difference to your energy bills, and as we all know keeping your boiler properly serviced makes sense and helps a lot with your energy usage. However, eventually every boiler has to be replaced, but how do you know when that is?

Some will say that you wait until your boiler breaks, but that is obviously not a solution that you really wish to follow, left to its own devices, a boiler will no doubt break on a holiday weekend in the middle of winter, just the time you need it most. Instead, you can be pro-active and make sure you get your new boiler before the old one stops completely, and get it fitted when it’s convenient for you.

Happily there are a few warning signs that show when your boiler is starting to fail that give you plenty of time to arrange a replacement boiler to be fitted before any problems materialize. With your boiler, you should be looking out for:

  • Loss of heat-If you find that the temperature is going down, this can indicate the boiler losing efficiency, a sure sign that it is getting past its useful life.
  • Noise-If you hear constant knocking, hissing, popping or any combination of these, it could be a sign of uneven water distribution, and a sign the boiler needs replacing.
  • Leaks-If you are seeing frequent leaks it is probably a good time to consider a replacement
  • Age-While modern boilers are well made and relatively reliable, they tend to lose efficiency over time and can start to develop frequent faults. If your boiler is 10 years old or beyond, it’s worth considering a replacement even if it is not giving you problems just yet.

With boilers, safe is better than sorry, so try and make sure you replace yours before it fails.


Most modern boilers are of the condensing type, making them much more efficient than older non-condensing boilers, but even so, you can make sure you get the very best performance from your boiler by following a few simple steps.

Condensing boilers include a large heat exchanger that ensures more heat from the flue gases are used for heating water than older boilers, and it is this that makes them more efficient. It also influences how the boiler is best used as well, specifically the condenser needs fairly cool water to be at its most effective, and so your radiators should be running at around 60 degrees C for the best effect.

Fitting a room thermostat can help tremendously with reducing your energy bills, keeping a constant temperature is also beneficial to health, so brings even more benefits. This also ties into another aspect of the system, and that is having it set at the right temperature. You can save a lot of money by having the temperature set right, most of us tend to have our thermostats set higher than we need, so try this trick. Turn the temperature down by one degree and leave it for a day. If you don’t feel too cool, turn it down again by another degree the next day. Keep repeating this until you feel uncomfortable. This may seem simple, but each 1 degree drop can save you around £90 per year on your heating costs, so is well worth doing.

The other important step is timing, the old adage that you should keep the heating on low all the time is a myth that doesn’t pass investigation, and it is much cheaper to simply have heat when you need it. Remember, you can set it to switch off about 20 minutes before you normally leave the house if you want to, the residual heat will keep you warm until you do actually leave.

Follow these simple steps for lower bills and a longer lasting, more efficient boiler.

Do you like this guide?